Обучение по природни науки и върхови технологии

2016/2, стр. 197 - 209

ACID MODIFIED BABY POWDER BASED TALK – A SORBENT MATERIAL FOR THIN-LAYER CHROMATOGRAPHY

Soner Ergül
E-mail: sergul@omu.edu.tr
Department of Science Education
Ondokuz Mayıs University
55200 Atakum Yerleşkesi-Samsun Turkey

Резюме: Baby powder based talc (BP) is modified by keeping in 0.3 M HCl solution at room temperature for 24 hours. The product, acid modified baby powder based talc, is called “modified-BPT”. Modified-BPT is investigated for their usefulness in the stationary phase of Thin-Liquid Chromatography (TLC). The separability of the components of a commercial ink has been tested on modified-BPT layers successfully. These results may be also said for the adaptability or validity on column chromatography.

Ключови думи: analytical chemistry, TLC, baby powder , modi fied baby powder talc, chromatography

Introduction

Chromatography is one of the most important analytical techniques used to separate components of mixtures. In chromatographic separations and teaching chromatography, the thin-layer chromatography (TLC) is often used as a quick, easy and separation method extensively used for organic species but rarely used for inorganic samples. While TLC is not common for inorganic cations, in the literature, some researchers have recently revealed that its utility is also valid for inorganic samples (Ergül, 2004; 2006; 2008; Mohammad et al., 2002; 2004; Mohammad & Jabeen, 2003; Mohammad & Agrawal, 2000; 2002; Mohammad, 1997; Mohammad & Khan, 1995; Ajwal et al., 1988; 1989a; 1989b; Mohammad & Fatima, 1987; Savaşcı & Akçay, 1999; Gürkan & Savaşcı, 2005).There are numerous applications of TLC for the qualitative and quantitative analysis of components of natural and artificial mixtures (Curtright et al., 1999; Baum & Shanks, 1975; Anwar, 1963; Goller, 1963; Rolins, 1963; Frodyma & Frei, 1969).

A number of minerals have previously been used as TLC adsorbents, including talc (Walsch, 1967), activated bentonite (Popov & Stefanov, 1968), kaolinite (Fayez et al., 1967), china clay (Sheen, 1971), activated bleaching earth (Hashimoto et al., 1965), modi fied perlite (Karaka ş & Yüksel, 1998), acid modi fi ed diatomaceous earth (Ergül et al., 2005; Ergül & Savaşcı, 2008). Silica gel and alumina have been used most frequently as adsorbents for the separation to components of the mixtures on TLC applications (Sthal, 1969).

Successful TLC separation depends on the properties of the sample, and also those of the mobile and stationary phases. Finding suitable resolution for a TLC application involves usually by changing the properties of mobile phase only. It does not involve by changing the properties of stationary phase although a possibility sorbent is present to change the properties of stationary phase (Ergül et al., 2005; Ergül & Savaşcı, 2008).

On TLC, adsorbent materials should be inexpensive and easily available. Besides, commercial baby powders are easily available products, and they are mixtures based on talc or corn starch as major components. Some commercial baby powders and their contents were given (Ergül, 2009). Talc as a major component of baby powder is a magnesium silicate mineral with the composition \(\mathrm{Mg}_{3}\left[\mathrm{Si}_{4} \mathrm{O}_{10}\right]\) \((\mathrm{OH})_{2}\) and a layered lattice structure. Its available surface for absorption markedly depends on particle size. Talc has been used as a TLC adsorbent to separate fatty acids, lanatosides, amino acids, the sugars and the flavonoids (Walsch, 1967; Sthal, 1969). In addition, the retention factors and separability of commercial ink components on thin layers prepared by acid modifi ed diatomaceous earth (Ergül et al., 2005), baby powder based talc (Ergül, 2009) and silica gel \(60 \mathrm{GF}_{254}\) (Ergül et al., 2005; Ergül, 2009) were examined and were discussed in the context of the variation of the stationary and mobile phases.

In practice, the modifi cation of the baby powder based talc has not been investigated yet. Therefore, in this study, the baby powder (BP) based talc was modifi ed by refluxing with acid processes. Modified BP (modified BPT) was used as stationary phase. The commercial ink samples were run on activated thin layers of acid modified BPT. The retention factors (\(\mathrm{R}_{\mathrm{F}}\) ) and separabilty of commercial ink components were examined and discussed in the context of the variation of stationary and mobile phase properties and the adaptability or validity on column chromatography. In addition, this layers was compared with already known \(\mathrm{R}_{\mathrm{F}}\), and separability of ink compenents on activated baby powder and \(\mathrm{Si}-60 \mathrm{GF}_{254}\) layers on cited literature.

Experimental

Chemicals, reagents, materials

Ammonia, n-butanol, acetic acid and ethanol were purchased from Merck (Darmstadt, Germany). Baby powder of Bebeten trademark was used to prepare modified BPT. Red and blue inks of Pelikan 4001 were used as the sample on TLC applications.

\(2 \mathrm{~mol} \mathrm{~L}^{-1}\) ammonia solution was prepared by adding distilled water to 150.4 mL of ammonia (\(\mathrm{d}=0.904 \mathrm{~g} / \mathrm{mL}, 25 \%\) ) on 1.0-L volumetric flask. Butanol-ethanol-2M ammonia (\(3: 1: 1, \mathrm{v} / \mathrm{v}\) ) and butanol-acetic acid-water (\(12: 3: 5, \mathrm{v} / \mathrm{v}\) ) mixtures were used as mobile phases. Modi fied BPT was used as stationary phases. The plates were prepared using a Loughborough-Griffin&George, TLC Unikit (Leicestershire, England). All the chemicals were of analytical grade.

Modifi cation of BP

200 mL of \(0.3 \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{HCl}\) was poured into a beaker and \(\mathrm{BP}(40 \mathrm{~g} \lt 50 \mu \mathrm{~m}\) particle size) was added to it and then was shaken at room temperature for 24 h. After, this suspension was filtered and washed until the filtrate gave a negative reaction for \(\mathrm{Cl}^{-}\). The product was dried at \(110^{\circ} \mathrm{C}\) for 24 h and then sized with a \(50 \mu \mathrm{~m}\) sieve. The product, acid modified baby powder based talc, was named modifi ed-BPT.

Preparation of thin layer plates from modifi ed-BPT

Slurries of modified-BPT in ethanol (\(1: 1.5, \mathrm{w} / \mathrm{v}\) ) were spreaded onto clean glass plates (\(7.5 \times 15 \mathrm{~cm}\) ) with a thickness of \(250 \mu \mathrm{~m}\) using a spreader kit. Non activated plates were obtained by keeping the plates at room temperature for 2 h. They were activated by heating in an oven at \(110^{\circ} \mathrm{C}\) for 1 h. For TLC applications, activated plates were used.

TLC applications

The red and blue ink samples and a mixture of both (\(1: 1, \mathrm{v} / \mathrm{v}\) ) were spotted with micropipettes on the starting line which was 2 cm from the bottom of the activated modified- BPT plates. The original spots on the layers were dried at room temperature for 5 min. A pencil line was marked 8 cm above the starting line of each plate. Two developing chambers measuring 10x50x20 cm were used. Sixty milliliters of butanol-ethanol-2M ammonia (\(3: 1: 1, \mathrm{v} / \mathrm{v}\) ) was poured into one chamber and 60 mL of butanol-acetic acid-water (12:3:5, v/v) into the other. The lids of the chamber were closed and the chambers allowed standing for 25 min to ensure saturation of the air in each chamber with solvent vapors. Then, activated modifi ed BPT plates with their ink samples were carefully immersed in the chambers. The plates, which were taken out of the chambers when the solvent fronts reached 8.0 cm above the starting line of each plate, were dried. The migration distances of the solvent (Zf each plate, were dried. The migration distances of the solvent \(\left(\mathrm{Z}_{\mathrm{f}}\right)\) and of each spot (\(\mathrm{Z}_{\mathrm{x}}\) ) were then measured.

The Measurements of pH

10 % süspensions of BP, modified BPT and \(\mathrm{Si}-60 \mathrm{GF}_{254}\) were individually prepared. The pH values of these süspansions, butanol-ethanol-2 M ammonia \((3: 1: 1\), \(\mathrm{v} / \mathrm{v}\) ) and butanol-acetic acid-water (12:3:5, v/v) mixtures were individually measured using pH meter. From the measurations, when the pH values of acidic and basic mobile phases were respectively 3.00 and \(11.00, \mathrm{pH}\) values of the slurries of Si-\(60 \mathrm{GF}_{254}\), BP and modified-BP as stationary phases were respectively \(7.00,9.00\) and 7.50.

Result

Successful TLC separation depends on the properties of the sample and also those of the mobile and stationary phases. Finding suitable resolution for a TLC application usually involves changing the properties of the mobile phase only. It does not involve changing the properties of the stationary phase.

Table 1. The \(\mathrm{R}_{\mathrm{f}}\) values for red and blue ink components obtained by using a acidic and basic mobile phases on activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\) (Ergül & Savaşcı, 2008; Ergül, 2009), BP (Ergül, 2009) and modifi ed-BP layers

ComponentCoupleSi-60GF254Activated BPModied-BPTaFRbFRaFRbFRaFRbFRPink0.91±0.050.71±0.040.91±0.050.86±0.040.94±0.050.84±0.04Yellow0.38±0.020.40±0.020.67±0.030.72±0.040.34±0.020.73±0.04Green0.56±0.030.56±0.030.67±0.030.54±0.030.59±0.030.60±0.03Dark Blue0.49±0.030.56±0.030.08±0.010.05±0.010.09±0.010.11±0.01

a: Butanol:acetic acid:water mixture (12:3:5, v:v:v), b: Butanol-ethanol-(2M) ammonia mixture (\(3: 1: 1, \mathrm{v} / \mathrm{v}\) ) Number of repeated runs: 3

In this study, to prepare a new stationary phase, the baby powder based talc was modifi ed by refl uxing with 3M HCl and modifi ed BPT was used as stationary phase for normal-phase TLC applications of commercial red and blue ink samples. Because of the ink components being acidic, basic or neutral, and also soluble in water, basic butanol-ethanol-2M ammonia (\(3: 1: 1, \mathrm{v} / \mathrm{v}\) ) and acidic butanol-acetic acid-water (12:3:5, v/v) mixtures were used as mobile phases. The chromatograms were given in Figs 1- 2 for the activated modified BPT plates. The developed spots of ink compenents could be determined easily with the naked eye. The retention factors \(\left(\mathrm{R}_{\mathrm{F}}\right)\) of the ink components were calculated from \(\mathrm{R}_{\mathrm{F}}=\mathrm{Z}_{\mathrm{x}} / \mathrm{Z}_{\mathrm{f}}\). The same procedure was also applied to the activated BP and the modified-BPT layers. From the chromatograms, the RFrom the chromatograms, the \(R_{F}\) values of ink components were given in Table I.

Separability on TLC and expected resolution on CC

On TLC application, the resolution is relation to separability parameter (\(r\) ) in context of different between \(\mathrm{R}_{\mathrm{F}}\) values of component couple. In addition, the separations by TLC are precursor for the applications on column chromatography. The retention factors and separability of components in the sample using TLC is related to the elution time and separability on column chromatography. In this context, the \(r\) parameter is quantitatively the measurement of expected resolution on column chromatography in this context of the separability of components on thin layer chromatography. It is calculated using Eq. (1) (Duncan, 1962).

Figure 1. Chromatograms of ink samples with butanol-acetic acid-water mixture \((12: 3: 5, \mathrm{v} / \mathrm{v})\). (a) on activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\) plate (b) on activated BP plate (c) on activated modified-BPT plate [1: red ink, 2: blue ink, 3: mixture of 1 and 2]

Figure 2. Chromatograms of ink samples with butanol-ethanol-amonnia (2M) mixture (\(3: 1: 1, \mathrm{v} / \mathrm{v}\) ). (a) on activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\) plate (b) on activated BP plate (c) on activated modified-BPT plate [1: red ink, 2: blue ink, 3: mixture of 1 and 2]

(1) \[ \mathrm{r}=\tfrac{\mathrm{a}}{\mathrm{~b}+0.1 \mathrm{a}} \]

In Eq. (1), \(a\) is \(\mathrm{R}_{\mathrm{F}}\) value of the fast moving substance A and \(b\) is \(\mathrm{R}_{\mathrm{F}}\) value of the slow moving substance B on the chromatograms respectively. The separability parameter is dimensionless number, which indicates whether separation on column chromatography is carried out or not. When mobile and stationary phases are same for column and thin layer chromatographic systems, it is said that the separation of two components may be possible when \(r\) is \( \gt 1\) (Duncan, 1962). In this study, \(r\) values of red and blue ink component couples obtained on thin layer chromatographic applications were given in Table 2.

Table 2. Expected resolution data on CC of component couples in ink samples

Component coupleSi-60GF254Activated BPModied-BPTrarbrarbrarbPink-Yellow1.9321.5071.1961.0672.1661.032Pink-Green1.3981.1251.1961.3741.3741.228Pink-Dark Blue1.5661.1255.3226.3245.1094.330Green- Dark Blue1.0260.9094.5585.1923.9603.529Green-Yellow1.2841.2280.9091.1771.4791.085Yellow-Dark Blue1.1420.9094.5585.9022.7423.989

a: Butanol:acetic acid:water mixture (12:3:5, v:v:v), b: Butanol-ethanol-(2M) ammonia mixture (\(3: 1: 1, \mathrm{v} / \mathrm{v}\) ) Number of repeated runs: 3.

Discussion

Evalation of Modifi cation

To prevent interference and the reacting of activated BP layer with acidic mobile phase was modified by refluxing with 3M HCl solution. The reacting and interfering inorganic compounds (such as ZnO, magnesium stearate) were converted to soluble salts and removed from baby powder based talc by refl uxing with acid processes. When pH value of baby powder based talc was 9.0, pH of modifi ed BPT was 7.5. Through the modifi cation process, the pH of the baby powder based talc changed from 9.0 to 7.5. Although the layers of baby powder based talc react with acidic mobile phase, modifie BPT layers do not react with acidic mobile phase. In addition, chromatographic parametres (such as \(\mathrm{R}_{\mathrm{F}}\) and \(r\) ) of both layers were differend from each other. These qualitative and quantitative indicators suggested that some interfering organic and inor ganic compounds had been successfully removed and mofi difaciton was succcesfuly carried out.

Evalation of Chromatograms

As shown in Figs 1 – 2, on the activated BP and modified BPT layers, the red ink was separated into yellow and pink spots when the solvent front values were \(\geq 2.0 \mathrm{~cm}\) for both acidic and basic mobile phases. The blue ink was separated into two main spots (dark blue and green) on running with the acidic and basic mobile phases when the solvent front was \(\geq 8.0 \mathrm{~cm}\). However, the blue ink components were not separated even when the solvent front was \(\geq 8.0 \mathrm{~cm}\) on running with basic mobile phase on \(\mathrm{Si}-60 \mathrm{GF}_{254}\) layer. In addition, dark blue spot has undergone to tailing, the other spots have not. The reason for tailing lies in the fact that it is related with both load capacity of the stationary phase and the amount of the components in the spots. Although the same amount of sample has been spotted to all of three kind layers, the dark blue spot on activated BP and activated modified BPT layers has been developed with tailing on running with acidic mobile phase, but the one on \(\mathrm{Si}-60 \mathrm{GF}_{254}\) has been developed without tailing. This situation indicates that the load capacity of \(\mathrm{Si}-60 \mathrm{GF}_{254}\) layer for dark blue is higher than those of activated BP and activated modified BPT layers. On the other hand, the area of dark blue spot is larger than those of green for three kinds of layers. This observation reveals that the amount of dark blue component on the sample is higher than those of green.

As shown in Figs 1 – 2, the chromaogram in Fig. 2b obtained with basic mobile phase on the activated BP layer is beige although the bottom section chromatogram in Fig. 1b obtained with acidic mobile phase on the activated BP layer is tight and turns into dirty beige. Those spoilt structures and color changing are qualitative indicators of chemical interaction of the stationary phase with mobile phase. The spoilt structure and color change are results of chemical interaction between the talc, \(\mathrm{Mg}_{3}\left[\mathrm{Si}_{4} \mathrm{O}_{10}\right](\mathrm{OH})_{2}\), on activated BP layer and the \(\mathrm{CH}_{3} \mathrm{COOH}\) in acidic mobile phase. On the other hand, no physical deformation and color change have been observed on the activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\) and modified BPT layers qualitatively . Consequently , it can be said that the modi fi ed BPT and \(\mathrm{Si}-60 \mathrm{GF}_{254}\) layers do not react with acidic and basic mobile phases although the activated BP layer undergoes to chemical decomposition on the application with the acidic mobile phase. However, it is possible to conclude that layers of activated BP layer have been successfully applied to the separation of components of ink samples also.

Effect of mobile phase changing to \(R_{F}\)

In Table I, for modified BPT layers, when the acidic mobile phase was replaced by the basic one, \(\mathrm{R}_{\mathrm{F}}\) value changed from \(0.34 \pm 0.02\) to \(0.73 \pm 0.04\) for the yellow component. \(\mathrm{R}_{\mathrm{F}}\) values for the pink, dark blue and green components did not change significantly although acidic mobile phase was replaced by the basic one. For \(\mathrm{Si}-60-\) \(\mathrm{GF}_{254}\) layers, when the acidic mobile phase was replaced by the basic one, \(\mathrm{R}_{\mathrm{F}}\) values changed significantly from \(0.91 \pm 0.05\) to \(0.71 \pm 0.04\) for the pink component. \(\mathrm{R}_{\mathrm{F}}\) values for the yellow, dark blue and green components did not change although mobile phase changed by basic one. For the activated BP layers, when acidic mobile phase was replaced by basic one, \(\mathrm{R}_{\mathrm{F}}\) values of components of ink samples change. On the basis of the experimental data and their changing patterns, the polarity , acidic and basic properties of the mobile phase was effective in contributing to the chromatographic behavior of all the dye components because of water soluble property.

Effect of Stationary Phase Changing to \(R_{F}\)

In Table I, when the modi fied BPT layer was replaced with the activated BP one, when using acidic mobile phase, the \(\mathrm{R}_{\mathrm{F}}\) value changed significantly from 0.34 \(\pm 0.02\) to \(0.67 \pm 0.03\) for the yellow component only. \(\mathrm{R}_{\mathrm{F}}\) values for the pink, dark blue and green components did not change significantly by both acidic and basic mobile phases although the modifi ed BPT layer was replaced by the activated BP one. On the other hand, when the modifi ed BPT layer was replaced with the activated Si-\(60 \mathrm{GF}_{254}\) one, when using acidic mobile phase, the \(\mathrm{R}_{\mathrm{F}}\) value changed significantly from \(0.09 \pm 0.01\) to \(0.49 \pm 0.03\) for the dark blue component. In addition, when the modified BPT layer was replaced with the activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\) one, when using basic mobile phase, the \(\mathrm{R}_{\mathrm{F}}\) values changed significantly the dark blue, pink and yellow components. \(\mathrm{R}_{\mathrm{F}}\) value for the green component did not change significantly by basic mobile phase although the modified BPT layer was replaced by the activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\) one. The chemical composition, pH and physical properties of the modified BPT, activated BP and Si-\(60 \mathrm{GF}_{254}\) are significantly different from each others. Thus, these data and chromatographic behavior patterns could not be explained easily. As a result, the retention of various molecules on stationary phase is generally explained by considering the interactions between polar \(\mathrm{Si}-\mathrm{OH}\) groups on surface of layer and molecules in sample, e.g., hydrogen bridging, dipole-dipole and Van der Waals. Thus, the change of \(\mathrm{R}_{\mathrm{F}}\) values of ink components on TLC applications on both adsorbents is related to surface activity of the layers.

Separability on TLC and expected resolution on CC

The data for the red and blue ink components obtained by using the acidic and basic mobile phases on the activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\), the activated BP and the modified BPT layers are given Tables II. In Table 2, the r values for pink-yellow couple which belong to red ink on the activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\), the activated BP and the modified BPT layers, when using acidic mobile phase are \(1.932,1.196\) and 2.166, respectively. In Table 2, the r values for pink-yellow couple on the activated Si-60GF254, the r values for pink-yellow couple on the activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\), the activated BP and the activated BPT layers, when using basic mobile phase are \(1.507,1.67\) and 1.032, respectively. Because the r values are \( \gt 1.0\) for pink-yellow couple, these chromatographic systems are effective to separate this couple. As a result, pink and yellow spots belong to red ink are successfully separated on all of chromatographic systems.

In Table 2, the r values for green-dark blue couple which belongs to on the activated Si-60GF \({ }_{254}\), the activated BP and the modified BPT layers, when using acidic mobile phase are \(1.026,4.558\) and 3. 960, respectively. \(r\) values for greendark blue couple which belongs to on the activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\), the activated BP and the modified BPT layers, when using basic mobile phase is \(0.909,5.192\) and 3.529, respectively. Yet these components of blue ink have developed only one spot without separation on activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\) layer. Because r value is \( \gt 1.0\) for green-dark blue-green couple, the activated BP and the activated BPT layers are successful to separate this couple on TLC applications using both kinds of mobile phases. However, \(\mathrm{Si}-60 \mathrm{GF}_{254}\) layer is not successful to separate this couple because of \(\mathrm{r} \lt 1.0(\mathrm{r}=0.909)\) and spot overlapping. Consequently, to separate the components of blue ink, the activated BP and activate BPT layers are more successful than \(\mathrm{Si}-60 \mathrm{GF}_{254}\) layers on TLC applications using both kinds of mobile phases.

As seen in Table 2, \(r\) parameters of pink-yellow, pink-green, pink-dark blue, greendark blue, green-yellow and yellow-dark blue ink component couples were bigger than 1.000 on all of chromatographic systems using the activated modifi ed-BPT layers. Therefore, it can be said that all of ink component couples were successfully separated on all of thin layer chromatographic systems using the modifi ed BPT layers because of \(r \gt 1.000\). In addition, the best analytical separ > 1.000. In addition, the best analytical separations of pink-yellow and green-yellow ink component couples on all of the chromatographic applications were obtained when using acidic mobile phase butanol:acetic acid:water mixture (12:3:5, \(\mathrm{v}: \mathrm{v}: \mathrm{v})\) as mobile phase on the activated modified BPT layer.

As seen in T able 2, \(r\) parameters of pink-yellow , pink-green, pink-dark blue ink compenent couples were bigger than 1.000 on all chromatographic systems.

Therefore, it can be said that these complex couples were successfully separated on all TLC systems because of \(r \gt 1.000\). In addition, the best analytical separ > 1.000. In addition, the best analytical separation of pink-green ink compenent couple was obtained when using butanol:acetic acid:water mixture \((12: 3: 5, \mathrm{v}: \mathrm{v}: \mathrm{v})\) as mobile phase on the activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\) layer. The best analytical separations of pink-dark blue, green-dark blue and yellowdark blue ink compenent couples were obtained when using butanol-ethanol-(2M) ammonia mixture (\(3: 1: 1, \mathrm{v} / \mathrm{v}\) ) as mobile phase on the activated BP layer.

As seen in Table 2, \(r\) parameters of green-dark blue, green-yellow and yellowdark blue were smaller than 1.00 on some chromatographic systems. On these chromatographic systems, the mobile phase was butanol-ethanol-(2M) ammonia mixture (\(3: 1: 1, \mathrm{v} / \mathrm{v}\) ) for green-dark blue and yellow-dark blue ink component couples when the stationary phase was activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\) phase. In addition, \(r\) value for green-yellow ink component couple was smaller than 1.0 when using butanol:acetic acid:water mixture (12:3:5, v:v:v) as mobile phase on activated BP layer. As a result, although these chromatographic systems were not successfully separated ink component couples cited, other chromatographic systems were successfully separated ink component couples. The mutual separation for all of ink components was obtained when using butanol:acetic acid:water mixture (12:3:5, \(\mathrm{v}: \mathrm{v}: \mathrm{v}\) ) as mobile phase on activated \(\mathrm{Si}-60 \mathrm{GF}_{254}\) and modified BPT layers. In addition, the mutual separation for all of ink components was obtained when using butanol-ethanol-(2 M ) ammonia mixture (\(3: 1: 1, \mathrm{v} / \mathrm{v}\) ) as mobile phase on activated BP and modified BPT layers. As a result, the best mutual separations are carried out on these chromatographic systems cited. It can be said that this result is also valid for column chromatography in context of \(r\) parameters of ink component couples.

Conclusions

This work was carried out to modifie baby powder based talc and to investigate the useful for TLC and the adaptability or validity on column chromatography of modified BPT. In light of these studies, conclusions are as follows: (a) the baby powder based talc was succesfully modified to the modified BPT by refl uxing with 3 M HCl. Being different of the pH values and chromatographic properties of BP and modified BPT are quantitative indicators of modification; (b) the modifi ed BPT and \(\mathrm{Si}-60 \mathrm{GF}_{254}\) layers do not react with acidic and basic mobile phases although the activated BP layer undergoes to chemical decomposition on the application with the acidic mobile phase; (c)pink and yellow spots belong to red ink are successfully separated on all of chromatographic systems; (d) to separate the components of blue ink, the activated BP and activate BPT layers are more successful than Si\(60 \mathrm{GF}_{254}\) layers on TLC applications using both kinds of mobile phases; (e) the best analytical separations of pink-yellow and green-yellow ink component couples on all of the chromatographic applications were obtained when using acidic mobile phase butanol:acetic acid:water mixture (12:3:5, v:v:v) as mobile phase on the activated modified BPT layer.

REFERENCES

Ajmal, M., Mohammad, A. & Fatima, N. (1988). Separation of microgram quantities of cadmium (II) from milligram quantities of zinc (II) and of copper (II) from nickel (II) and cobalt (II) with

aqueous sodium formate halogen anion systems. Microchem. J., 37, 314 – 321.

Ajmal, M., Mohammad, A. & Fatima, N. (1989a). Sodium molybdate impregnated silica-gel layers as stationary phase for chromatographicseparation of metal-ions. J. Indian Chem. Soc., 66, 425-426.

Ajmal, M., Mohammad, A., Fatima, N. & Khan, A.H. (1989b). Determination of microquantities of mercury (II) with preliminary thin-layer chromatographic-separation from mercury (I), lead (II), nickel (II), and copper (II) on acid-treated silica-gel layers - recovery of mercury (II) from river waters and industrial wastewater. Microchem. J., 39, 361 – 371.

Anwar, M.H. (1963). Separation of plant pigments by thin layer chromatography. J. Chem. Educ., 40, 29 – 30.

Baum, D.E. & Shanks, R.A. (1975). A novel method for quantitative thin layer chromatography. J. Chem. Educ., 52, 738.

Curtright, R.D., Emry, R. & Markwell, J. (1999). Student understanding of chromatography: a hands-on approach. J. Chem. Educ., 76, 249 – 251.

Duncan. G.R. (1962). The transfer of chromatoplate resolutions to lar ge scale separations on adsorbtion colums. A new apparatus for producing thin layers. J. Chromatogry A, 8, 37 – 43.

Ergül, S. (2004). Qualitative analysis of \(\mathrm{Cu}^{2+}, \mathrm{Co}^{2+}\) and \(\mathrm{Ni}^{2+}\) cations using thin layer chromatography. J. Chromat. Sci., 42, 121 – 124.

Ergül, S. (2006). Investigation of thin-layer chromatography properties of some transition metal complexes based on ditiocarbamates. J. Chromat. Sci., 44, 543 – 547.

Ergül, S. (2008). Linkage between separation of Cu 2+, Co 2+, and Ni 2+ on of \(\mathrm{Cu}^{2+}, \mathrm{Co}^{2+}\), and \(\mathrm{Ni}^{2+}\) on TLC and crystal fi eld theory. J. Chromat. Sci., 46, 907 – 911.

Ergül, S. (2009). Using of baby powder based talc as a thin layer chromatography adsorbent: teaching chemical experiment. Chemistry, 18, 42 – 55.

Ergül, S. & Savaşcı, Ş. (2008). Acid modified diatomaceous earth - a sorbent material for thin layer chromatography. J. Chromat. Sci., 46, 308 – 315.

Ergül, S., Kadan, İ., Savascı, Ş. & Ergül, S. (2005). Diatomaceous earth as a principle stationary phase component on TLC. J. Chromat. Sci., 43 , 394 – 400.

Fayez, M.B.E., Gad, G., Nasr, I. & Radvan, A.S. (1967). Sinai clay, a new adsorbent for thin layer chromatography. J. Chem. UAR, 10: 49 – 54.

Frodyma, M.M. & Frei, R.W. (1969). Reflectance spectroscopic analysis of dyes separated by thin layer chromatography. J. Chem. Educ., 46, \(522-\) 524.

Goller, E.J. (1965). Cation analysis with thin layer chromatography. \(J\). Chem. Educ., 42, 442 – 443.

Gürkan, R. & Savaşcı, Ş. (2005). Investigation of separation and identifi cation possibilities of some metal-DEDTC complexes by sequential TLC-IR systems. J. Chromat. Sci., 43, 324 – 330.

Hashimoto, A., Hitorani, A. & Mukai, K. (1965). Separation of alcohols by thin layer chromatography on activated bleaching earth. \(J\). Chromatography, 14, 343 – 347.

Karakaş, R. & Yüksel, Ü. (1998). Modifi cation of perlite for use as a thinlayer chromatography on activated bleaching earth. J. Chromat. Sci., 36, 499 – 504.

Mohammad, A. (1997). Thin-layer chromatographic methods for the identification, estimation, and separation of toxic metals in environmental samples; J. Planar Chromatography - Modern TLC, 10, 48 – 54.

Mohammad, A. & Agrawal, V. (2000). Applicability of surfactant-modifi ed mobile phases in thin-layer chromatography of transition metal cations: identification and separation of zinc (II), cadmium (II), and mercury (II) in their mixtures. J. Planar Chromatography - Modern TLC, 13, 210 –216.

Mohammad, A. & Agrawal, V. (2002). Use of cationic micellar mobile phases in normal-phase TLC for enhanced selectivity in the separation of transition metal ions: simultaneous separation of mixtures of zinc, nickel, mercury, and cadmium or manganese cations. Acta Chromatographıca, 12, 177 – 188.

Mohammad, A. & Fatima, N. (1987). Cation thin-layer chromatography in mixed organic-solvents containing s-butylamine - separation of Zn (II) from Cd (II) and Cu (II); Chromatographia, 23, 653 – 656.

Mohammad, A. & Jabeen, N. (2003). Soil-thin layer chromatography of heavy metal cations with surfactant-modified mobile phases: mutual separation of zinc (II), cadmium (II), and mercury (II). J. Planar Chromatography - Modern TLC, 16, 137 – 143.

Mohammad, A. & Khan, M.A.M. (1995). Thin-layer chromatographicseparation of zinc from Cd (II), Hg (II) and Ni (II) in environmentalsamples using impregnated silica layers. J. Chr omat. Sci., 33 , 531 – 535.

Mohammad, A., Iraqi, E. & Khan, I. A. (2002). Use of nonionic poly(ethylene glycol) p-isooctyl-phenyl ether (triton x-100) surfactant mobile phases in the thin-layer chromatography of heavy-metal cations. J. Chromat. Sci., 40, 162 – 169.

Mohammad, A., Agrawal, V. & Hena, S. (2004). Adsorption studies of metal cations on a silica static flat bed using anionic micellar mobile-phase systems sontaining carboxylic acids: Separation of co-existing iron (III), copper (II) and nickel (II) cations. Adsorption Science & Technology, 22, 89 – 105.

Popov, A. & Stefanov, K. (1968). Einsatz des aktivierten Bentonits als Adsorbens bei der Dünnschichtchromatographie. Compt. R. Acad. Bulg. Sci., 21, 673 – 675.

Rollins, C. (1963). Thin layer chromatographic separation of leaf pigments: a rapid demonstration. J. Chem. Educ., 40, 32.

Savaşcı, Ş. & Akçay, M. (1996). The determination of some heavy metal cations by TLC/photodensitometry. Turkish J. Chem., 20, 146 – 152.

Sheen, B. (1971). Chine clay – a sorbent for thin-layer chromatography. \(J\). Chromatography A, 60, 363 – 370.

Sthal, E. (1969). Thin-layer chromatography. New York: Springer.

Walsch, B.J.M. (1967). The use of talc as a TLC adsorbent. J. Chem. Educ., 44, 294 – 296.

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ИНОВАЦИИ В БОРБАТА С ТУМОРНИ ОБРАЗУВАНИЯ – ЛЕЧЕНИЕ ЧРЕЗ БРАХИТЕРАПИЯ

Георги Върбанов, Радостин Михайлов, Деница Симеонова, Йорданка Енева

NATURAL RADIONUCLIDES IN DRINKING WATER

Natasha Ivanova, Bistra Manusheva

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АДАПТИРАНЕ НА ОБРАЗОВАНИЕТО ДНЕС ЗА УТРЕШНИЯ ДЕН

И. Панчева, М. Недялкова, П. Петков, Х. Александров, В. Симеонов

INTEGRATED ENGINEERING EDUCATION: THE ROLE OF ANALYSIS OF STUDENTS’ NEEDS

Veselina Kolarski, Dancho Danalev, Senia Terzieva

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ZAGREB CONNECTION INDICES OF \(\mathrm{TiO}_{2}\) NANOTUBES

Sohaib Khalid, Johan Kok, Akbar Ali, Mohsin Bashir

SYNTHESIS OF NEW 3-[(CHROMEN-3-YL) ETHYLIDENEAMINO] -PHENYL] -THIAZOLIDIN-4ONES AND THEIR ANTIBACTERIAL ACTIVITY

Ramiz Hoti, Naser Troni, Hamit Ismaili, Malesore Pllana, Musaj Pacarizi, Veprim Thaçi, Gjyle Mulliqi-Osmani

2017 година
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GEOECOLOGICAL ANALYSIS OF INDUSTRIAL CITIES: ON THE EXAMPLE OF AKTOBE AGGLOMERATION

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TECHNOGENESIS OF GEOECOLOGICAL SYSTEMS OF NORTHEN KAZAKHSTAN: PROGRESS, DEVELOPMENT AND EVOLUTION

Kulchichan Dzhanaleyeva, Gulnur Mazhitova, Altyn Zhanguzhina, Zharas Berdenov, Tursynkul Bazarbayeva, Emin Atasoy

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47-А НАЦИОНАЛНА КОНФЕРЕНЦИЯ НА УЧИТЕЛИТЕ ПО ХИМИЯ

В последните години тези традиционни за българското учителство конфе- ренции се организират от Българското дружество по химическо образование и история и философия на химията. То е асоцииран член на Съюза на химици- те в България, който пък е член на Европейската асоциация на химическите и

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Candra Purnawan, Sayekti Wahyuningsih, Dwita Nur Aisyah

EFFECT OF DIFFERENT CADMIUM CONCENTRATION ON SOME BIOCHEMICAL PARAMETERS IN ‘ISA BROWN’ HYBRID CHICKEN

Imer Haziri, Adem Rama, Fatgzim Latifi, Dorjana Beqiraj-Kalamishi, Ibrahim Mehmeti, Arben Haziri

PHYTOCHEMICAL AND <i>IN VITRO</i> ANTIOXIDANT STUDIES OF <i>PRIMULA VERIS</i> (L.) GROWING WILD IN KOSOVO

Ibrahim Rudhani, Florentina Raci, Hamide Ibrahimi, Arben Mehmeti, Ariana Kameri, Fatmir Faiku, Majlinda Daci, Sevdije Govori, Arben Haziri

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„СИМВОЛНИЯТ КАПИТАЛ“ НА БЪЛГАРСКОТО УЧИЛИЩЕ

Николай Цанков, Веска Гювийска

KINETICS OF PHOTO-ELECTRO-ASSISTED DEGRADATION OF REMAZOL RED 5B

Fitria Rahmawati, Tri Martini, Nina Iswati

ALLELOPATHIC AND IN VITRO ANTICANCER ACTIVITY OF STEVIA AND CHIA

Asya Dragoeva, Vanya Koleva, Zheni Stoyanova, Eli Zayova, Selime Ali

NOVEL HETEROARYLAMINO-CHROMEN-2-ONES AND THEIR ANTIBACTERIAL ACTIVITY

Ramiz Hoti, Naser Troni, Hamit Ismaili, Gjyle Mulliqi-Osmani, Veprim Thaçi

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OPTIMIZATION OF ENGINE OIL FORMULATION USING RESPONSE SURFACE METHODOLOGY AND GENETIC ALGORITHM: A COMPARATIVE STUDY

Behnaz Azmoon, Abolfazl Semnani, Ramin Jaberzadeh Ansari, Hamid Shakoori Langeroodi, Mahboube Shirani, Shima Ghanavati Nasab

CHEMOMETRICASSISTEDSPECTROPHOTOMETRIC ESTIMATION OF LANSOPRAZOLE AND DOMEPERIDONE IN BULK AND COMMERCIAL DOSAGE FORM

Farheen Sami, Shahnaz Majeed, Tengku Azlan Shah Tengku Mohammed, Noor Fatin Amalina Kamaruddin, Mohammad Zulhimi Atan, Syed Amir Javid Bukhari, Namra, Bushra Hasan, Mohammed Tahir Ansari

EVALUATION OF ANTIBACTERIAL ACTIVITY OF DIFFERENT SOLVENT EXTRACTS OF <i>TEUCRIUM CHAMAEDRYS</i> (L. ) GROWING WILD IN KOSOVO

Arben Haziri, Fatmir Faiku, Roze Berisha, Ibrahim Mehmeti, Sevdije Govori, Imer Haziri

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ПРИРОДОНАУЧНАТА ГРАМОТНОСТ НА УЧЕНИЦИТЕ В НАЧАЛОТО НА XXI ВЕК – В ТЪРСЕНЕ НА КОНЦЕПТУАЛНО ЕДИНСТВО

Теодора Коларова, Иса Хаджиали, Мимия Докова, Веселин Александров

COMPUTER SIMULATORS: APPLICATION FOR GRADUATES’ADAPTATION AT OIL AND GAS REFINERIES

Irena O. Dolganova, Igor M. Dolganov, Kseniya A. Vasyuchka

SYNTHESIS OF NEW [(3-NITRO-2-OXO-2H-CHROMEN4-YLAMINO) -PHENYL] -PHENYL-TRIAZOLIDIN-4-ONES AND THEIR ANTIBACTERIAL ACTIVITY

Ramiz Hoti, Hamit Ismaili, Idriz Vehapi, Naser Troni, Gjyle Mulliqi-Osmani, Veprim Thaçi

STABILITY OF RJ-5 FUEL

Lemi Türker, Serhat Variş

A STUDY OF BEGLIKTASH MEGALITHIC COMPLEX

Diana Kjurkchieva, Evgeni Stoykov, Sabin Ivanov, Borislav Borisov, Hristo Hristov, Pencho Kyurkchiev, Dimitar Vladev, Irina Ivanova

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2016 година
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THE EFFECT OF KOH AND KCL ADDITION TO THE DESTILATION OF ETHANOL-WATER MIXTURE

Khoirina Dwi Nugrahaningtyas, Fitria Rahmawati, Avrina Kumalasari

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VOLTAMMERIC SENSOR FOR NITROPHENOLS BASED ON SCREEN-PRINTED ELECTRODE MODIFIED WITH REDUCED GRAPHENE OXIDE

Arsim Maloku, Liridon S. Berisha, Granit Jashari, Eduard Andoni, Tahir Arbneshi

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ИЗСЛЕДВАНЕ НА ПРОФЕСИОНАЛНО-ПЕДАГОГИЧЕСКАТА РЕФЛЕКСИЯ НА УЧИТЕЛЯ ПО БИОЛОГИЯ (ЧАСТ ВТОРА)

Надежда Райчева, Иса Хаджиали, Наташа Цанова, Виктория Нечева

EXISTING NATURE OF SCIENCE TEACHING OF A THAI IN-SERVICE BIOLOGY TEACHER

Wimol Sumranwanich, Sitthipon Art-in, Panee Maneechom, Chokchai Yuenyong

NUTRIENT COMPOSITION OF CUCURBITA MELO GROWING IN KOSOVO

Fatmir Faiku, Arben Haziri, Fatbardh Gashi, Naser Troni

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CONTEXT-BASED CHEMISTRY LAB WORK WITH THE USE OF COMPUTER-ASSISTED LEARNING SYSTEM

N. Y. Stozhko, A. V. Tchernysheva, E.M. Podshivalova, B.I. Bortnik

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ПО ПЪТЯ ON THE ROAD

Б. В. Тошев

INTERDISCIPLINARY PROJECT FOR ENHANCING STUDENTS’ INTEREST IN CHEMISTRY

Stela Georgieva, Petar Todorov, Zlatina Genova, Petia Peneva

2015 година
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COMPLEX SYSTEMS FOR DRUG TRANSPORT ACROSS CELL MEMBRANES

Nikoleta Ivanova, Yana Tsoneva, Nina Ilkova, Anela Ivanova

SURFACE FUNCTIONALIZATION OF SILICA SOL-GEL MICROPARTICLES WITH EUROPIUM COMPLEXES

Nina Danchova, Gulay Ahmed, Michael Bredol, Stoyan Gutzov

INTERFACIAL REORGANIZATION OF MOLECULAR ASSEMBLIES USED AS DRUG DELIVERY SYSTEMS

I. Panaiotov, Tz. Ivanova, K. Balashev, N. Grozev, I. Minkov, K. Mircheva

KINETICS OF THE OSMOTIC PROCESS AND THE POLARIZATION EFFECT

Boryan P. Radoev, Ivan L. Minkov, Emil D. Manev

WETTING BEHAVIOR OF A NATURAL AND A SYNTHETIC THERAPEUTIC PULMONARY SURFACTANTS

Lidia Alexandrova, Michail Nedyalkov, Dimo Platikanov

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TEACHER’S ACCEPTANCE OF STUDENTS WITH DISABILITY

Daniela Dimitrova-Radojchikj, Natasha Chichevska-Jovanova

APPLICATION OF LASER INDUCED BREAKDOWN SPECTROSCOPY AS NONDESDUCTRIVE AND SAFE ANALYSIS METHOD FOR COMPOSITE SOLID PROPELLANTS

Amir Hossein Farhadian, Masoud Kavosh Tehrani, Mohammad Hossein Keshavarz, Seyyed Mohamad Reza Darbany, Mehran Karimi, Amir Hossein Rezayi

THE EFFECT OF DIOCTYLPHTHALATE ON INITIAL PROPERTIES AND FIELD PERFORMANCE OF SOME SEMISYNTHETIC ENGINE OILS

Azadeh Ghasemizadeh, Abolfazl Semnani, Hamid Shakoori Langeroodi, Alireza Nezamzade Ejhieh

QUALITY ASSESSMENT OF RIVER’S WATER OF LUMBARDHI PEJA (KOSOVO)

Fatmir Faiku, Arben Haziri, Fatbardh Gashi, Naser Troni

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БЛАГОДАРЯ ВИ!

Александър Панайотов

ТЕМАТА ВЪГЛЕХИДРАТИ В ПРОГРАМИТЕ ПО ХИМИЯ И БИОЛОГИЯ

Радка Томова, Елена Бояджиева, Миглена Славова, Мариан Николов

BILINGUAL COURSE IN BIOTECHNOLOGY: INTERDISCIPLINARY MODEL1)

V. Kolarski, D. Marinkova, R. Raykova, D. Danalev, S. Terzieva

ХИМИЧНИЯТ ОПИТ – НАУКА И ЗАБАВА

Елица Чорбаджийска, Величка Димитрова, Магдалена Шекерлийска, Галина Бальова, Методийка Ангелова

ЕКОЛОГИЯТА В БЪЛГАРИЯ

Здравка Костова

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SYNTHESIS OF FLUORINATED HYDROXYCINNAMOYL DERIVATIVES OF ANTI-INFLUENZA DRUGS AND THEIR BIOLOGICAL ACTIVITY

Boyka Stoykova, Maya Chochkova, Galya Ivanova, Luchia Mukova, Nadya Nikolova, Lubomira Nikolaeva-Glomb, Pavel Vojtíšek, Tsenka Milkova, Martin Štícha, David Havlíček

SYNTHESIS AND ANTIVIRAL ACTIVITY OF SOME AMINO ACIDS DERIVATIVES OF INFLUENZA VIRUS DRUGS

Radoslav Chayrov, Vesela Veselinova, Vasilka Markova, Luchia Mukova, Angel Galabov, Ivanka Stankova

NEW DERIVATIVES OF OSELTAMIVIR WITH BILE ACIDS

Kiril Chuchkov, Silvia Nakova, Lucia Mukova, Angel Galabov, Ivanka Stankova

MONOHYDROXY FLAVONES. PART III: THE MULLIKEN ANALYSIS

Maria Vakarelska-Popovska, Zhivko Velkov

LEU-ARG ANALOGUES: SYNTHESIS, IR CHARACTERIZATION AND DOCKING STUDIES

Tatyana Dzimbova, Atanas Chapkanov, Tamara Pajpanova

LACTOBACILLUS PLANTARUM AC 11S AS A BIOCATALYST IN MICROBIAL ELECYTOLYSIS CELL

Elitsa Chorbadzhiyska, Yolina Hubenova, Sophia Yankova, Dragomir Yankov, Mario Mitov

STUDYING THE PROCESS OF DEPOSITION OF ANTIMONY WITH CALCIUM CARBONATE

K. B. Omarov, Z. B. Absat, S. K. Aldabergenova, A. B. Siyazova, N. J. Rakhimzhanova, Z. B. Sagindykova

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TEACHING CHEMISTRY AT TECHNICAL UNIVERSITY

Lilyana Nacheva-Skopalik, Milena Koleva

ФОРМИРАЩО ОЦЕНЯВАНЕ PEER INSTRUCTION С ПОМОЩТА НА PLICКERS ТЕХНОЛОГИЯТА

Ивелина Коцева, Мая Гайдарова, Галина Ненчева

VAPOR PRESSURES OF 1-BUTANOL OVER WIDE RANGE OF THEMPERATURES

Javid Safarov, Bahruz Ahmadov, Saleh Mirzayev, Astan Shahverdiyev, Egon Hassel

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РУМЕН ЛЮБОМИРОВ ДОЙЧЕВ (1938 – 1999)

Огнян Димитров, Здравка Костова

NAMING OF CHEMICAL ELEMENTS

Maria Atanassova

2014 година
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LUBRICATION PROPERTIES OF DIFFERENT PENTAERYTHRITOL-OLEIC ACID REACTION PRODUCTS

Abolfazl Semnani, Hamid Shakoori Langeroodi, Mahboube Shirani

ALLELOPATHIC AND CYTOTOXIC ACTIVITY OF ORIGANUM VULGARE SSP. VULGARE GROWING WILD IN BULGARIA

Asya Pencheva Dragoeva, Vanya Petrova Koleva, Zheni Dimitrova Nanova, Mariya Zhivkova Kaschieva, Irina Rumenova Yotova

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GENDER ISSUES OF UKRAINIAN HIGHER EDUCATION

Н.H.Petruchenia, M.I.Vorovka

МНОГОВАРИАЦИОННА СТАТИСТИЧЕСКА ОЦЕНКА НА DREEM – БЪЛГАРИЯ: ВЪЗПРИЕМАНЕ НА ОБРАЗОВАТЕЛНАТА СРЕДА ОТ СТУДЕНТИТЕ В МЕДИЦИНСКИЯ УНИВЕРСИТЕТ – СОФИЯ

Радка Томова, Павлина Гатева, Радка Хаджиолова, Зафер Сабит, Миглена Славова, Гергана Чергарова, Васил Симеонов

MUSSEL BIOADHESIVES: A TOP LESSON FROM NATURE

Saâd Moulay Université Saâd Dahlab de Blida, Algeria

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ЕЛЕКТРОННО ПОМАГАЛO „ОТ АТОМА ДО КОСМОСА“ ЗА УЧЕНИЦИ ОТ Х КЛАС

Силвия Боянова Професионална гимназия „Акад. Сергей П. Корольов“ – Дупница

ЕСЕТО КАТО ИНТЕГРАТИВЕН КОНСТРУКТ – НОРМАТИВЕН, ПРОЦЕСУАЛЕН И ОЦЕНЪЧНО-РЕЗУЛТАТИВЕН АСПЕКТ

Надежда Райчева, Иван Капурдов, Наташа Цанова, Иса Хаджиали, Снежана Томова

44<sup>-ТA</sup> МЕЖДУНАРОДНА ОЛИМПИАДА ПО ХИМИЯ

Донка Ташева, Пенка Василева

ДОЦ. Д.П.Н. АЛЕКСАНДЪР АТАНАСОВ ПАНАЙОТОВ

Наташа Цанова, Иса Хаджиали, Надежда Райчева

COMPUTER ASSISTED LEARNING SYSTEM FOR STUDYING ANALYTICAL CHEMISTRY

N. Y. Stozhko, A. V. Tchernysheva, L.I. Mironova

С РАКЕТНА ГРАНАТА КЪМ МЕСЕЦА: БОРБА С ЕДНА ЛЕДЕНА ЕПОХА В ГОДИНАТА 3000 СЛЕД ХРИСТА. 3.

С РАКЕТНА ГРАНАТА КЪМ МЕСЕЦА:, БОРБА С ЕДНА ЛЕДЕНА ЕПОХА, В ГОДИНАТА 000 СЛЕД ХРИСТА. .

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ВИСША МАТЕМАТИКА ЗА УЧИТЕЛИ, УЧЕНИЦИ И СТУДЕНТИ: ДИФЕРЕНЦИАЛНО СМЯТАНЕ

Б. В. Тошев Българско дружество за химическо образование и история и философия на химията

ВАСИЛ ХРИСТОВ БОЗАРОВ

Пенка Бозарова, Здравка Костова

ЖИВАТА ПРИРОДА

Б. В. Тошев

БИБЛИОГРАФИЯ НА СТАТИИ ЗА МИСКОНЦЕПЦИИТЕ В ОБУЧЕНИЕТО ПО ПРИРОДНИ НАУКИ ВЪВ ВСИЧКИ ОБРАЗОВАТЕЛНИ НИВА

Б. В. Тошев Българско дружество за химическо образование и история и философия на химията

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BOTYU ATANASSOV BOTEV

Zdravka Kostova, Margarita Topashka-Ancheva

CHRONOLOGY OF CHEMICAL ELEMENTS DISCOVERIES

Maria Atanassova, Radoslav Angelov

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КАК ДА МОТИВИРАМЕ УЧЕНИЦИТЕ OT VII КЛАС ДА УЧАТ

Маргарита Бозова, Петко Бозов

ОБРАЗОВАНИЕ ЗА ПРИРОДОНАУЧНА ГРАМОТНОСТ

Адриана Тафрова-Григорова

2013 година
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DIFFERENTIAL TEACHING IN SCHOOL SCIENCE EDUCATION: CONCEPTUAL PRINCIPLES

G. Yuzbasheva Kherson Academy of Continuing Education, Ukraine

АНАЛИЗ НА ПОСТИЖЕНИЯТА НА УЧЕНИЦИТЕ ОТ ШЕСТИ КЛАС ВЪРХУ РАЗДЕЛ „ВЕЩЕСТВА И ТЕХНИТЕ СВОЙСТВА“ ПО „ЧОВЕКЪТ И ПРИРОДАТА“

Иваничка Буровска, Стефан Цаковски Регионален инспекторат по образованието – Ловеч

HISTORY AND PHILOSOPHY OF SCIENCE: SOME RECENT PERIODICALS (2013)

Chemistry: Bulgarian Journal of Science Education

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„Образователни стандарти и природонаучна грамотност“ – това е темата на състоялата се от 25 до 27 октомври 2013 г. в Габрово 45. Национална конфе- ренция на учителите по химия с международно участие, която по традиция се проведе комбинирано с Годишната конференция на Българското дружество за химическо образование и история и философия на химията. Изборът на темата е предизвикан от факта, че развиването на природонаучна грамотност е обща тенденция на реформите на учебните програми и главна

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ЗА ХИМИЯТА НА БИРАТА

Ивелин Кулев

МЕТЕОРИТЪТ ОТ БЕЛОГРАДЧИК

Б. В. Тошев Българско дружество за химическо образование и история и философия на химията

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RECASTING THE DERIVATION OF THE CLAPEYRON EQUATION INTO A CONCEPTUALLY SIMPLER FORM

Srihari Murthy Meenakshi Sundararajan Engineering College, India

CHEMICAL REACTIONS DO NOT ALWAYS MODERATE CHANGES IN CONCENTRATION OF AN ACTIVE COMPONENT

Joan J. Solaz-Portolés, Vicent Sanjosé Universitat de Valènciа, Spain

POLYMETALLIC COMPEXES: CV. SYNTHESIS, SPECTRAL, THERMOGRAVIMETRIC, XRD, MOLECULAR MODELLING AND POTENTIAL ANTIBACTERIAL PROPERTIES OF TETRAMERIC COMPLEXES OF Co(II), Ni(II), Cu(II), Zn(II), Cd(II) AND Hg(II) WITH OCTADENTATE AZODYE LIGANDS

Bipin B. Mahapatra, S. N. Dehury, A. K. Sarangi, S. N. Chaulia G. M. Autonomous College, India Covt. College of Engineering Kalahandi, India DAV Junior College, India

ПРОФЕСОР ЕЛЕНА КИРКОВА НАВЪРШИ 90 ГОДИНИ

CELEBRATING 90TH ANNIVERSARY OF PROFESSOR ELENA KIRKOVA

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SIMULATION OF THE FATTY ACID SYNTHASE COMPLEX MECHANISM OF ACTION

M.E.A. Mohammed, Ali Abeer, Fatima Elsamani, O.M. Elsheikh, Abdulrizak Hodow, O. Khamis Haji

FORMING OF CONTENT OF DIFFERENTIAL TEACHING OF CHEMISTRY IN SCHOOL EDUCATION OF UKRAINE

G. Yuzbasheva Kherson Academy of Continuing Education, Ukraine

ИЗСЛЕДВАНЕ НА РАДИКАЛ-УЛАВЯЩА СПОСОБНОСТ

Станислав Станимиров, Живко Велков

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COLORFUL EXPERIMENTS FOR STUDENTS: SYNTHESIS OF INDIGO AND DERIVATIVES

Vanessa BIANDA, Jos-Antonio CONSTENLA, Rolf HAUBRICHS, Pierre-Lonard ZAFFALON

OBSERVING CHANGE IN POTASSIUM ABUNDANCE IN A SOIL EROSION EXPERIMENT WITH FIELD INFRARED SPECTROSCOPY

Mila Ivanova Luleva, Harald van der Werff, Freek van der Meer, Victor Jetten

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Рафаил ПОПОВ

УЧИЛИЩНИ ЛАБОРАТОРИИ И ОБОРУДВАНЕ SCHOOL LABORATORIES AND EQUIPMENT

Учебни лаборатории Илюстрации от каталог на Franz Hugershoff, Лайциг, притежаван от бъдещия

2012 година
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ADDRESING STUDENTS’ MISCONCEPTIONS CONCERNING CHEMICAL REACTIONS AND SYMBOLIC REPRESENTATIONS

Marina I. Stojanovska, Vladimir M. Petruševski, Bojan T. Šoptrajanov

АНАЛИЗ НА ПОСТИЖЕНИЯТА НА УЧЕНИЦИТЕ ОТ ПЕТИ КЛАС ВЪРХУ РАЗДЕЛ „ВЕЩЕСТВА И ТЕХНИТЕ СВОЙСТВА“ ПО ЧОВЕКЪТ И ПРИРОДАТА

Иваничка Буровска, Стефан Цаковски Регионален инспекторат по образованието – Ловеч

ЕКОТОКСИКОЛОГИЯ

Васил Симеонов

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Проф. Методий Попов (1881-1954) Госпожици и Господа студенти,

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КОНЦЕПТУАЛНА СХЕМА НА УЧИЛИЩНИЯ КУРС П О ХИМИЯ – МАКР О СКОПСКИ ПОДХОД

Б. В. Тошев Българско дружество за химическо образование и история и философия на химията

ROLE OF ULTRASONIC WAVES TO STUDY MOLECULAR INTERACTIONS IN AQUEOUS SOLUTION OF DICLOFENAC SODIUM

Sunanda S. Aswale, Shashikant R. Aswale, Aparna B. Dhote Lokmanya Tilak Mahavidyalaya, INDIA Nilkanthrao Shinde College, INDIA

SIMULTANEOUS ESTIMATION OF IBUPROFEN AND RANITIDINE HYDROCHLORIDE USING UV SPECTROPHOT O METRIC METHOD

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