Analyses of Non-steroidal Anti-inflammatory Drugs in Environmental Water Samples with Microemulsion Electrokinetic Chromatography

Abstract

In this study, a microemulsion electrokinetic chromatography (MEEKC) was used to analyze ten non-steroidal antiinflammatory drugs (NSAIDs) in water samples. The type and ratio of organic modifiers were found to be the predominant influences on the NSAIDs separation. Subsequently, field-amplified sample injection was coupled with this MEEKC method in order to enhance the detection sensitivity. When both the acid plug (3 s) and water plug (5 s) were placed at the front of the capillary, and the acetonitrile (ACN) solvent was added to the water plug (10% ACN) and the sample matrix (15% ACN), the separation time was shortened to 15 min, as well as the limit of detection (LOD) of these NSAIDs was reduced to the range of 0.03 to 0.3 μg/L, which provided about a 1400-fold to 6100-fold enhancement in LOD. Finally, the proposed on-line concentration MEEKC method also successfully determined the NSAIDs residues in water samples after solid-phase extraction.

Recent advances in enrichment techniques for trace analysis in capillary electrophoresis

“…Some highlighted applications of FA in CE are summarized in Table , that is, using such FA modes as LVSS , PAEKI , FESI , electrokinetic stacking injection , and NSM . Various compounds such as halogenated phenols, SAs, sulfonylurea herbicides, plasma arginine, and dimethylated arginines have been determined after FA enrichment from environmental samples (e.g., water and soil samples), biological samples (e.g., urine, blood, plasma, and liver), food samples (e.g., grape), and pharmaceutical samples (e.g., herb medicine).…”

A review of developments in the methodology and application of microemulsion electrokinetic chromatography

“…Kuo et al developed an MEEKC method coupled with FASI (anion selective) for the rapid separation and sensitive detection of ten nonsteroidal anti‐inflammatory drugs (NSAIDs).…”

“…The introduction of water or acidic/basic plugs prior to the sample can have a profound effect on enrichment factors through increasing the injection volume and improving stacking. An acid plug (phosphate buffer pH 2) and a water plug (to increase electric field strength and hence increase the amount of analyte electrokinetically injected) were introduced prior to the sample for the analysis of NSAIDs . The lengths of acid and water plugs were also optimized in order to achieve the maximum stacking capability.…”

“…The addition of ACN to the sample matrix causes stacking due to its low conductivity in a high field strength region, hence the solute molecule has a greater velocity in the injection medium than in the separation medium . Kuo et al modified the water and acid plugs with ACN prior to injection of the sample in order to improve stacking ability for the NSAIDs. Furthermore, the sample solution (borax‐boric acid buffer pH 8) was modified with various concentration of ACN from 0 to 15% v/v.…”

Chromatography of Non-Steroidal Anti-Inflammatory Drugs: New Achievements

“…LOD of NSAIDs was between 0.03 and 0.3 µg/L. It was stated that the method is suitable for the analysis of NSAIDs in water samples after solid-phase extraction (SPE) [20].…”