Wyniki wyszukiwania - BazTech

1

Chromatographic behavior of performance-enhancing drugs on thin layers of bismuth silicate ion exchanger

Hassankhani-Majd Z., Ghoulipour V., Husain S. W.

Acta Chromatographica

|

2006

|

No. 16

173-180

EN

The chromatographic behavior of amphetamine, bemegride, caffeine, chlorphentermine, ephedrine, ethylamphetamine, isoproterenol, methadone, methylendioxyamphetamine, pentazocine, pethidine, pemoline, strychnine, and salbutamol has been studied on thin layers of bismuth silicate anion exchanger with organic, aqueous, and mixed organic-aqueous mobile phases. Rapid separations of one drug from many other drugs and also many quaternary, ternary, and binary separations have been achieved and are discussed. A new variable, SRF has been introduced to quantify the separating power of the bismuth silicate anion exchanger in thin-layer chromatography.

2

Chromatographic behaviour of antibiotics on thin layers of an inorganic ion-exchanger

Husain S. W., Ghoulipour V., Sepahrian H.

Acta Chromatographica

|

2004

|

No. 14

102-109

EN

The chromatographic behaviour of amoxicillin, ampicillin, cepha-lexin, cloxacillin, doxycycline, tetracycline, erythromycin, gentamycin, stre-ptomycin, and co-trimoxazole has been studied on thin layers of titanic silicate inorganic ion-exchanger with organic, aqueous, and mixed aqueous–organic mobile phases. Rapid separations of one antibiotic from numerous other antibiotics have been achieved, as have many binary and ternary separations. Salting-out TLC using aqueous ammonium sulphate solutions revealed the dependence of RF values on the concentration of salt in the mobile phase, and the existence of a linear relationship between RM and molarity of (NH4)2SO4 for some antibiotics. The effect of varying the vo-lume ratio of the binary mobile phase methanol–0.1 M formic acid on the RF values of the antibiotics has also been studied.

3

Multiresidue determination of diazinon and ethion in pistachio nuts by use of matrix solid phase dispersion with a lanthanum silicate co-column and gas chromatography

Husain S. W., Kiarostami V., Morrovati M., Tagebakhsh M. R.

Acta Chromatographica

|

2003

|

No. 13

208-214

EN

Diazinon and ethion in pistachio nuts have been analyzed by use of matrix solid-phase dispersion (MSPD) followed by gas chromatography with nitrogen-phosphorus detection (GC-NPD). The efficiency of different adsorbents (C18, cyano, phenyl, and amino) for MSPD of pistachio nuts was compared. Lanthanum silicate ion-exchanger was used as co-column material. Recoveries for C18-MSPD co-column lanthanum silicate were 95% for ethion and 94% for diazinon with relative standard deviations of 7-13% in the concentration range 0.5-4 mg kg-1. The limits of detection were 0.02 mg kg-1 for ethion and 0.035 mg kg-1 for diazinon; these were lower than the maximum residue limits (MRL) established by WHO/FAO. Thin-layer chromatography was performed on lanthanum silicate and lanthanum tungstate ion exchangers to ensure the pesticide residues were present in the final MSPD extract.

4

Inorganic ion-exchangers for quantitative TLC of toxic elements. V. Separation and determination of chromium(VI)

Ghoulipour V., Husain S. W.

Acta Chromatographica

|

2002

|

No. 12

170-176

EN

A simple, rapid, and selective method has been developed for the separation and determination of Cr(VI) from Al(III), Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Se(IV), Sr(II), Zr(IV), Cd(II), La(III), Ce(III), Hg(II), and U(VI). Separation was accomplished in 12.5 cm migration distance and 14 min migration time on titanic silicate ion-exchange plates with 0.4 M ammonium oxalate - 2.2 M aqueous ammonia, 1:1 (v/v), as mobile phase. Quantitative measurement of the separated zones of Cr(VI) was achieved by scanning densitometry at ? = 545 nm.