HPLC with pulsed amperometric detection for sorbitol as a biomarker for diabetic neuropathy.

This study describes the optimal analytical conditions for sorbitol analysis by a high-performance anion-exchange chromatography-pulsed amperometric detection method. Its clinical utility as a diagnostic tool was established by measuring sorbitol in the sciatic nerves or salivary glands of diabetes mellitus-induced mice. Sorbitol was completely separated from other monosaccharides on an anion-exchange column with 100mM NaOH as eluent. The limit of detection (S/N=3) and limit of quantification (S/N=10) were 0.03 ng (3 ng/g) and 0.10 ng (10 ng/g), respectively. The linear dynamic range was 0.01-50.0 microg/g (r(2)=0.9997 and 0.9989 for sciatic nerves and salivary glands, respectively), and the mean recoveries for intra- or inter-day assays were in the range of 98.5-103.9%. This method easily identified diabetic and normal groups, making it a practical procedure for the rapid screening of diabetic neuropathy.