Quantification of lactate in synovia by microchip with contactless conductivity detection

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.