Quantitative determination of isoniazid in biological samples by cation-selective exhaustive injection–sweeping–micellar electrokinetic chromatography

Abstract

Tuberculosis (TB), an infectious disease caused by Mycobacterium tuberculosis, infects approximately one third of the current world population. Isoniazid is one of the most frequently used first-line anti-TB drugs. In this study, we developed a sensitive cation-selective exhaustive injection-sweeping-micellar electrokinetic chromatography method (CSEI-Sweep-MEKC) for analyzing isoniazid in human plasma. Parameters including acetonitrile (ACN) percentage in the separation buffer; the injection time, and concentration of the high-conductivity buffer; sodium dodecyl sulfate (SDS) concentration; phosphate concentration in the sample matrix; and the sample injection time were all optimized to obtain the best analytical performance. The optimal background electrolyte comprised 50 mM phosphate buffer, 100 mM SDS, and 15% ACN. Non-micelle background electrolyte, containing 75 mM phosphate buffer and 15% ACN, was first injected into the capillary, followed by a short plug of 200 mM phosphate (high-conductivity buffer). Run-to-run repeatability (n=3) and intermediate precision (n=3) of peak area ratios were found to be lower than 8.7% and 11.4% RSD, respectively. The accuracy of the method was within 98.1-106.9%. The limit of detection of isoniazod in human plasma was 9 ng mL(-1). Compared with conventional MEKC, the enhancement factor of the CSEI-Sweep-MEKC method was 85 in plasma samples. The developed method was successfully used to determine isoniazid concentration in patient plasma. The results demonstrated that CSEI-Sweep-MEKC has the potential to analyze isoniazid in human plasma for therapeutic drug monitoring and clinical research.

Micellar electrokinetic chromatography: A review of methodological and instrumental innovations focusing on practical aspects

“…Thus, tobacco‐specific N ‐nitrosamines in human urine , methadone and its metabolites in serum from heroin addicts , and isoniazid in patient plasma were successfully determined at picogram per milliliter levels thanks to the increased enrichment factors obtained (6000‐ to 15 000‐fold in some cases ). In general, an effective SPE or liquid–liquid extraction procedure is additionally used to improve the determination of the analytes in these complex biological matrices. Li et al used the CSEI‐sweeping approach to determine cypromazine and its metabolite melamine at picogram per milliliter levels in dairy products.…”

“…As in the previous review, CSEI‐sweeping has been exploited to a greater extent than ASEI‐sweeping and its applications have focused on the determination of drugs and their metabolites in biological samples. Thus, tobacco‐specific N ‐nitrosamines in human urine , methadone and its metabolites in serum from heroin addicts , and isoniazid in patient plasma were successfully determined at picogram per milliliter levels thanks to the increased enrichment factors obtained (6000‐ to 15 000‐fold in some cases ). In general, an effective SPE or liquid–liquid extraction procedure is additionally used to improve the determination of the analytes in these complex biological matrices.…”

Determination of brompheniramine enantiomers in rat plasma by cation‐selective exhaustive injection and sweeping cyclodextrin modified electrokinetic chromatography method

“…It was suggested that the higher the S‐β‐CD concentration, the higher the sweeping power. In theory, a high sweeping power could improve the enhancement efficiency during sweeping procedure . Seen from Table , it could be found that resolutions and migration times gradually increased with the stepwise increase in the concentration of S‐β‐CD from 5 to 30 mg/mL, which is mainly caused by the increased interactions between S‐β‐CD and enantiomers.…”

Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips (2010–2012)

“…In the last two years, most applications featuring sequential stacking approaches with sweeping were performed for biochemical components and food/food contaminants. Popularly used was CSEI‐sweeping . Other sequential stacking techniques employed were anion‐selective exhaustive injection (ASEI)‐sweeping , dynamic pH junction‐sweeping , LVSS‐sweeping , t‐ITP‐sweeping , sweeping‐MSS .…”