Lactate determination in human vitreous humour by capillary electrophoresis and time of death investigation

Abstract

Forensic inquests, particularly, in assessing time since death currently recognize the importance of the analysis of vitreous humour (VH) biomarkers. Present research, studies, and validates the determination of lactate (La) in VH by CZE with indirect UV detection. The BGE (pH 8.9) consisted of Tris buffer (37 mM) containing 4‐methoxybenzoic acid (4 mM) and alkyl‐trimethyl‐ammonium bromide (1.2 mM). Each VH specimen was diluted with a butyric acid solution (internal standard 0.057 mM) and La and butyrate were separated within 3–5 min (30 kV). The La LOQ and LOD were 4 and 2 mM, respectively. The calibration curve linearity ranged from 4 to 80 mM; intra‐ and interruns precisions were less than 10% for standard as well as for VH specimen, respectively. To investigate postmortem interval (PMI) and VH lactate level correlation, human VH specimens were collected during autopsy (n = 40) and stored at −20°C until assay. La levels ranged from 16 to 42 mM; PMI values ranged from 10 to 141 h. La (mM) and PMI (h) correlation was statistically significant (r2 = 0.527; p < 0.05). In conclusion, the present CZE analysis is efficacious to determine VH La as a biomarker for PMI investigation.

Estimation of Time Since Death Using Biochemical Markers in Synovial Fluid

“…The regression equation was found to be y = 6.6033 x + 112.74. There were no other studies done in synovial fluid lactate levels for estimating time since death to compare our results, but a similar statistically significant positive correlation was obtained with the vitreous lactate levels in a study done by Bertaso et al 12 in 2020, with R 2 = 0.5268, P < 0.05, with regression equation of y = 0.1682 x + 20.29.…”

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].…”