The reactive α-oxoaldehydes glyoxal (GO), methylglyoxal (MGO) and 3-deoxyglucosone (3-DG) have been linked to diabetic complications and other age-related diseases. Numerous techniques have been described for the quantification of α-oxoaldehydes in blood or plasma, although with several shortcomings such as the need of large sample volume, elaborate extraction steps or long run-times during analysis. Therefore, we developed and evaluated an improved method including sample preparation, for the quantification of these α-oxoaldehydes in blood and plasma with ultra performance liquid chromatography tandem mass spectrometry (UPLC MS/MS). EDTA plasma and whole blood samples were deproteinized using perchloric acid (PCA) and subsequently derivatized with o-phenylenediamine (oPD). GO, MGO and 3-DG concentrations were determined using stable isotope dilution UPLC MS/MS with a run-to-run time of 8 min. Stability of α-oxoaldehyde concentrations in plasma and whole blood during storage was tested. The concentration of GO, MGO and 3-DG was measured in EDTA plasma of non-diabetic controls and patients with type 2 diabetes (T2DM). Calibration curves of GO, MGO and 3-DG were linear throughout selected ranges. Recoveries of these α-oxoaldehydes were between 95% and 104%. Intra- and inter-assay CVs were between 2% and 14%. To obtain stable and reliable α-oxoaldehyde concentrations, immediate centrifugation of blood after blood sampling is essential and the use of EDTA as anticoagulant is preferable. Moreover, immediate precipitation of plasma protein with PCA stabilized α-oxoaldehyde concentrations for at least 120 min. With the use of the developed method, we found increased plasma concentrations of GO, MGO and 3-DG in T2DM as compared with non-diabetic controls.

Background. Plasma and urinary levels of D-lactate have been linked to the presence of diabetes. Previously developed techniques have shown several limitations to further evaluate D-lactate as a biomarker for this condition.Methods. D- and L-lactate were quantified using ultraperformance liquid chromatography tandem mass spectrometry with labelled internal standard. Samples were derivatized with diacetyl-L-tartaric anhydride and separated on a C₁₈-reversed phase column. D- and L-lactate were analysed in plasma and urine of controls, patients with inflammatory bowel disease (IBD), and patients with type 2 diabetes (T2DM).Results. Quantitative analysis of D- and L-lactate was achieved successfully. Calibration curves were linear (r2>0.99) over the physiological and pathophysiological ranges. Recoveries for urine and plasma were between 96% and 113%. Inter- and intra-assay variations were between 2% and 9%. The limits of detection of D-lactate and L-lactate in plasma were 0.7 μmol/L and 0.2 μmol/L, respectively. The limits of detection of D-lactate and L-lactate in urine were 8.1 nmol/mmol creatinine and 4.4 nmol/mmol creatinine, respectively. Plasma and urinary levels of D- and L-lactate were increased in patients with IBD and T2DM as compared with controls.Conclusion. The presented method proved to be suitable for the quantification of D- and L-lactate and opens the possibility to explore the use of D-lactate as a biomarker.