title: Study of cloud point extraction and high-performance liquid chromatographic determination of isoniazid based on the formation of isonicotinylhydrazone.
abstract: Isoniazid (INH) reacted with p-dimethylaminobenzaldehyde (DABD) in the presence of trichloroacetic acid to give isonicotinylhydrazone (INZ) having lambda(max) 365nm. Cloud point extraction (CPE) is carried out to extract INH and IHZ in aqueous solutions using surfactant poly(ethylene glycol) 4000 (PEG4000), respectively. Langmuir model is used to study the adsorption behaviors of the two solutes on micelles of PEG4000. A linear correlation is found between variation of PEG4000 concentration required for feed concentration of the two solutes and used to predict PEG4000 concentration required for extracting INH and IHZ in CPE procedure. The results calculated show that, for a desired recovery level of 90%, only can IHZ be sufficiently extracted by PEG4000. In this experiment, the feed concentration of PEG4000 is defined by above-mentioned correlation, and the effects of other operating parameters, e.g., concentration of salt, pH and centrifugation time on extraction of PEG4000-IHZ system have also been studied in detail. The proposed CPE method coupled with HPLC-UV system is successfully used for the determination of INH in urine sample.
authors.affiliation: College of Science, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, China.
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Zhou
authors.forename: Dao-Yuan
authors.initials: DY
authors.lastname: Zhao
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Zhao
authors.forename: Ming-Min
authors.initials: MM
authors.lastname: Yang
mesh_terms: D053000:Analytic Sample Preparation Methods; D000995:Antitubercular Agents / Q000737:chemistry*; D001547:Benzaldehydes / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007538:Isoniazid / Q000737:chemistry* / Q000652:urine*; D011092:Polyethylene Glycols / Q000737:chemistry; D015203:Reproducibility of Results; D012492:Salts / Q000737:chemistry; D012680:Sensitivity and Specificity; D013501:Surface-Active Agents / Q000737:chemistry; D014376:Tuberculosis / Q000652:urine
chemical_list: D000995:Antitubercular Agents; D001547:Benzaldehydes; D012492:Salts; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; C510241:p-dimethylaminobenzaldehyde; D007538:Isoniazid