Determination of Methyl Benzenesulfonate and Ethyl Benzenesulfonate in Amlodipine Besylate Tablets by UPLC-MS
This paper established a UPLC-MS method for the determination of methyl and ethyl benzenesulfonate in amlodipine besylate tablets.The gradient elution was performed for the determination of methyl and ethyl benzenesulfonate through a 10 mmol/L ammonium acetate-methanol mobile phase system using a Thermo Gold C18(1.9 μm,2.1 × 50 mm)column with a flow rate of 0.3 mL/min,an injection volume of 5 μL and a column temperature of 40℃.Optimized mass spectrometry based on methyl benzenesulfonate(quantitative ion pair 173.1/155.1,qualitative ion pair 173.1/91.0)and ethyl benzenesulfonate(quantitative ion pair 204.0/159.1)showed that the linearity of the method was good[y=1 080x+467(r=0.999 8)(methyl benzenesulfonate),y=23 7x+189(r=0.999 9)(ethyl benzenesulfonate)].The precision of methyl benzenesulfonate and ethyl benzenesulfonate was 94.0 and 97.3%respectively,the accuracy was 101.9%and 99.3%respectively,the RSD was 1.8%and 1.4%(n=12)respectively[RSD was 4.5%and 4.2%(n=9)],and the detection limit was both 1 ng/mL.Results showed that the method was rapid,sensitive and reproducible,and can be used to quantitatively determine the residues of methyl benzenesulfonate and ethyl benzenesulfonate in amlodipine benzenesulfonate tablets.