Sub-Minute Analysis of Lactate from a Single Blood Drop Using Capillary Electrophoresis with Contactless Conductivity Detection in Monitoring of Athlete Performance

A simple and fast method for the analysis of lactate from a single drop of blood was developed. The finger-prick whole blood sample (10 mu L) was diluted (1:20) with a 7% (w/v) solution of [tris(hydroxymethyl)methylamino] propanesulfonic acid and applied to a blood plasma separation device. The device accommodates a membrane sandwich composed of an asymmetric polysulfone membrane and a supporting textile membrane that allows the collection of blood plasma into a narrow glass capillary in less than 20 s. Separated and simultaneously diluted blood plasma was directly injected into a capillary electrophoresis instrument with a contactless conductivity detector (CE-(CD)-D-4) and analyzed in less than one minute. A separation electrolyte consisted of 10 mmol/L l-histidine, 15 mmol/L dl-glutamic acid, and 30 mu mol/L cetyltrimethylammonium bromide. The whole procedure starting from the finger-prick sampling until the CE-(CD)-D-4 analysis was finished, took less than 5 min and was suitable for monitoring lactate increase in blood plasma during incremental cycling exercise. The observed lactate increase during the experiments measured by the developed CE-(CD)-D-4 method correlated well with the results from a hand-held lactate analyzer (R = 0.9882). The advantage of the developed CE method is the speed, significant savings per analysis, and the possibility to analyze other compounds from blood plasma.

Automated summary

A simple and fast method for lactate analysis from a single drop of blood was developed, which involves dilution of a finger-prick whole blood sample and separation using a specialized device. The entire process, from sampling to analysis, takes less than 5 minutes and shows good correlation with results from a hand-held lactate analyzer. The developed method offers speed, cost savings, and the ability to analyze other compounds in blood plasma.