Three-phase solvent bar liquid-phase microextraction combined with high-performance liquid chromatography to determine sarcosine in human urine.

Sarcosine is a potential prostate cancer marker. In this study, we developed a method of three-phase solvent bar liquid-phase microextraction combined with high-performance liquid chromatography to determine sarcosine after derivatization with 4-dimethylarminoazobenzene-4-sulfonyl chloride from human urine. The effects of different extraction conditions on extraction efficiency were investigated and optimized. Under optimum experimental conditions, a calibration graph exhibited linearity over the range of 0.05-25 µmol/L with a correlation coefficient (r2 ) of 0.9990. The enrichment factor was 168, and the detection limit was 0.02 µmol/L. The method was successfully used to analyze sarcosine in human urine and non-invasive detection, and good spiked recoveries ranging from 90.5 to 93.6% were obtained. The proposed method exhibited high sensitivity, high enrichment factor, good precision, and a simple setup. It may contribute to the early accurate diagnosis and the progression monitoring of prostatic carcinoma.