Determination of α-solanine, α-chaconine and solanidine in plasma and urine by ultra-performance liquid chromatography-triple quadrupole mass spectrometry

Abstract

An ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS) method was developed for the determination of α-solanine, α-chaconine and solanidine in plasma and urine. The sample was acidified with aqueous solution containing 2% (v/v if not specified) formic acid, and then cleaned-up by solid-phase extraction with a mixed-mode cation exchange (MCX) cartridge. The analysis of the glycoalkaloids was carried out on an Acquity UPLC BEH Cl8 column (50 mm×2. 1 mm, 1. 7 μm) with gradient elution of acetoni-trile (containing 0. 1% formic acid) and H2O (containing 0.05% formic acid and 5.0 mmol/L ammonium acetate). The analytes were detected by positive electrospray ionization tandem mass spectrometry in MRM mode, and quantified by external matrix-matched standard calibra-tion. The cycle time of each analysis was 5. 5 min. The calibration curves were linear in the range of 0. 3-100 ng/mL of the glycoalkaloids in plasma and urine. The correlation coefficients were 0.997-0.999. The limits of detection (S/N =3) and quantitation (S/N = 10) were 0. 1 ng/mL and 0. 3 ng/mL. The average recoveries were 82%-112% and 96%-114% for the glycoal-kaloids spiked in plasma and urine, respectively, with relative standard deviations of 4. 0% -16% and 2. 7%-17% (n = 6). The method is simple, accurate and sensitive to detect the gly-coalkalo ds n plasma and ur ne for both cl n cal and forens c purposes.