Zhou Zhi-Ming, Zhao Dao-Yuan, Wang Jing, Zhao Wei-Jun, Yang Ming-Min
College of Science, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, China.
J Chromatogr A. 2009 Jan 2;1216(1):30-5. doi: 10.1016/j.chroma.2008.11.028. Epub 2008 Nov 18.
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.
异烟肼（INH）在三氯乙酸存在下与对二甲氨基苯甲醛（DABD）反应，生成最大吸收波长为365nm的异烟腙（INZ）。采用浊点萃取（CPE）法，分别用表面活性剂聚乙二醇4000（PEG4000）从水溶液中萃取INH和IHZ。用Langmuir模型研究了两种溶质在PEG4000胶束上的吸附行为。发现两种溶质进料浓度所需的PEG4000浓度变化之间存在线性相关性，可用于预测CPE过程中萃取INH和IHZ所需的PEG4000浓度。计算结果表明，对于90%的目标回收率，PEG4000只能充分萃取IHZ。本实验通过上述相关性确定PEG4000的进料浓度，并详细研究了其他操作参数，如盐浓度、pH值和离心时间对PEG-4000-IHZ体系萃取的影响。所提出的CPE方法与HPLC-UV系统联用成功用于尿液样品中INH的测定。
