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

Abstract

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 µL) 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-C4D) 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 µmol/L cetyltrimethylammonium bromide. The whole procedure starting from the finger-prick sampling until the CE-C4D 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-C4D 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.

Application of capillary electrophoresis with capacitively contactless conductivity detection for biomedical analysis

“…Therefore, the determination formate in blood and urinary oxalate and citrate is very important for diagnosis and management of diseases. CE-C 4 D has been demonstrated as a satisfactory method for the determination of various types of small organic ions, such as oxalate, citrate, [77], lactate [78][79][80], lactate and pyruvate [81,82], formate [83][84][85], oxalate, formate, and glycolate [86], and fluoroacetate [87]. The analyses of organic acids such as γ-hydroxybutyric acid in urine and serum [88], valproic acid (VPA) [89], organic acids in urine [90], uric acid in plasma and human urine [91], Ghydroxybutyric acid, ibotenic acid, and psilocybin in saliva [92], and urinary ethylmalonic acid [93] employing CE-C 4 D were also reported.…”

Capillary electrophoresis with capacitively coupled contactless conductivity detection (C4D) for rapid and simple determination of lactate in sweat

“…Lactate has been determined in biological samples mostly using enzymatic-and nonenzymatic-based sensors [12,[14][15][16][17][18]. However, other methods, such as CE [19][20][21][22], HPLC [23], and spectroscopy [24,25], can also be used. The determination of lactate in sweat has recently been extensively explored using colorimetric [26][27][28][29] and wearable electrochemical sensors [6,8,17,18,30 ].…”

“…Moreover, CE consumes small amounts of samples and reagents and generates low volumes of waste, making it environmental friendly. Therefore, several studies can be found in the literature regarding lactate determination by CE in various samples, particularly in biological matrices such as vitreous humor [19], exhaled breath condensate [22], plasma [21], and blood [20]. The application of CE for sweat analysis has also been explored [31][32][33][34][35][36][37][38][39][40], particularly for chloride determination aiming to diagnose cystic fibrosis [31-33, 35, 31, 38].…”