Detection of content and isotope abundance of ¹'5N-S-benzyl-L-cysteine

A HPLC method for determination of S-benzyl-L-cysteine in fermentation broth was established. Cosmosil C18 column (5 μm, 150 mm × 4.6 mm) was used with 2, 4-dinitrofluorobenzene as derivatization reagent and 0.05 mol/L sodium acetate buffer (pH = 6.5, including 10 mL/L N, N-dimethylformamide) and V(acetonitrile) : V(water) = 3 : 1 as mobile phase. The content was detected at a flow rate of 1.0 mL/min (gradient), the detection wavelength was 350 nm, column temperature was 30℃. The calibration curves were linear in the range of 0.2-1.0 g/L(R² = 0.9986), the average recovery rates were 97.30%, the minimum limit was 3.95 × 10^-4 g/L, the relative standard deviation of results was 0.55%. Microscale high temperature combustion-MS method was also described to detect the isotope abundance of ¹⁵N-SBC. The minimum consumption of ¹⁵N-SBC product was 2 mg, the optimal combustion temperature was 530℃ and reaction time was 3 h. The RSD of results was 0.17%. (authors)