Capillary electrophoresis with contactless conductometric detection for rapid screening of formate in blood serum after methanol intoxication

A new method for rapid, direct determination of formate in blood serum samples by capillary electrophoresis with contactless conductometric detection is presented. A selective separation of formate was achieved in approximately 1 min using an electrolyte system comprising 10 mM l-histidine, 15 mM glutamic acid and 30 μM cetyltrimethylammonium bromide at pH 4.56. The only sample preparation was dilution (1:100) with deionized water. The limit of detection and limit of quantitation was 2.2 μM and 7.3 μM, respectively, which corresponds to 0.22 mM and 0.73 mM in undiluted blood serum. The method provides a simple and rapid diagnostic test in suspected methanol intoxication cases. The method has been successfully tested on determination of formate in blood of a patient admitted to the hospital under acute methanol intoxication. The peak concentration of formate detected in the patient blood serum was 12.4 mM, which is 10- to 100-fold higher than the normal values in healthy population. The developed method presents the fastest test currently available to detect formate in blood samples.

► A new method for rapid analysis of formic acid by CE with C4D was developed. ► Formic acid is analyzed in blood serum samples in less than 2 min. ► No sample preparation except dilution with DI water is required. ► The method provides a simple diagnostic test for methanol intoxication. ► The method was successfully tested on patients with acute methanol intoxication.