摘要:

Methods are described for the separation, detection, and quantification of the thio (PS-containing) dialkyl phosphates O,O-dimethyl phosphorothionate (DMTP), O,O-dimethyl phosphorodithioate (DMDTP), O,O-diethyl phosphorothionate (DETP), and O,O-diethyl phosphorodithioate (DEDTP) by thin layer chromatography. The compounds were separated on C18chemically bonded silica gel plates and detected with TCQ chromogenic reagent; calibration curves were prepared by densitometric scanning of a range of standard aliquots.

ISSN:1082-6076    

DOI:10.1081/JLC-100101649

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A simple and rapid densitometric method has been developed for simultaneous determination of betamethasone valerate and miconazole nitrate in cream preparations. After extraction of the analyte with 96 % ethanol, the extracts were spotted on pre–coated silica gel plates, which were eluted two times with a mixture of chloroform–acetone–glacial acetic acid, 34+4+3 (v/v/v). Quantitative evaluation was performed by measuring the absorbance reflectance of the analyte spots at λ = 233 nm. The densitometric method is selective, precise, and accurate, and can be used for routine analysis of the cream preparations in pharmaceutical industry quality control laboratories.

ISSN:1082-6076    

DOI:10.1081/JLC-100101650

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A quantitative method involving high-performance thin-layer chromatography (HPTLC) with automated sample application and UV-absorption scanning densitometry was developed for the determination of diphenhydramine hydrochloride in tablets, gelcaps, and capsules. Separation was performed on high performance silica gel plates containing fluorescent indicator, and the analyte was detected as fluorescence-quenched zones under short-wave UV light. Four different pharmaceutical products containing diphenhydramine hydrochloride as an active ingredient were nalyzed to test the applicability of the new method. Precision was validated by replicate analysis of samples and accuracy by analysis of spiked samples. The percent diphenhydramine hydrochloride in the tested pharmaceutical samples ranged from 86.8% to 111% compared to label values, precision ranged from 1.7% to 1.9% relative standard deviation, and the errors in the two spiking experiments were 0.00% and 0.81% compared to the fortification levels.

ISSN:1082-6076    

DOI:10.1081/JLC-100101651

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Two overpressured layer chromatography (OPLC) systems were developed for the screening of toxicologically relevant basic drugs in forensic and clinical contexts. The OPLC1 system was trichloroethylene - methylethylketone -n-butanol - acetic acid - water 17+8+25+6+4 and the OPLC2 system was butyl acetate - ethanol - tripropylamine - water 85+9.25+5+0.75 with presaturation. Both systems were tested on high performance silica gel plates. The Rfvalues of the drugs were reproducible, the peak shapes were symmetrical, and the chromatographic systems showed low mutual correlation (r = 0.103). The separation numbers (SN) were 27.5 and 29.2 for OPLC1 and OPLC2, respectively, which are more than two times higher than those obtained with TLC systems in general. The combination of the systems was demonstrated to be feasible in the screening for drugs in autopsy urine samples, utilizing automated identification by hRfc/UV library search with combined dual-system reporting.

ISSN:1082-6076    

DOI:10.1081/JLC-100101652

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor