This article describes the determination of lactate in synovia by microchip capillary electrophoresis (MCE) integrated with contactless conductivity detection (CCD). The optimal running buffer consists of 10 mM tris(hydroxymethyl)aminomethane, 1 mM HCl , and 0.1 mM hexadecyltrimethylammonium bromide (pH 9.1). The quantitative measurement of lactate in dilute synovia samples can be finished in less than 40 s. The results indicated that the peak area had a good linear relationship with lactate concentration in the range of 20 to 1000 μM, and the correlation coefficient was 0.9984. The average recovery was from 96.6% to 106.1%, and the interday relative standard deviation was less than 4.0% ( n = 6). The limit of detection (signal/noise = 3) reached 6.5 μM. To validate the assay results, we compared the current method with the high-performance liquid chromatography method by measuring lactate in synovia samples. The data analysis verified that there was no significant difference between the two methods. Due to significant features such as low cost, integration, and miniaturization, the MCE–CCD method may have great potential in clinical diagnosis.
A simple glass/PDMS microfluidic chip for on-line sample pretreatment and contactless conductivity detection, which consisted of a 0.17 mm-thick glass cover and a PDMS substrate embedded with an SPE monolithic column, was presented in this paper. Using this integrated microchip system, sample extraction, injection, separation and detection were automatically performed in sequence. A sample of auramine O was concentrated by molecularly imprinted SPE (MISPE), eluted to sample reservoir, and injected by electromigration into separation channel for electrophoresis separation and contactless conductivity detection, with the calculated detection limit (S/N = 3) being 2.5 μg mL − 1 . The monolithic column was utilized to quantitatively extract auramine O , yielding an on-line enrichment factor of about 12. The microchip system is reliable and applicable to the analysis of auramine O in food sample.
危险品化学品经营许可证（带存储）