毛细管电泳-质谱联用法测定糖蜜酒精废液中的有机酸

建立了毛细管电泳质谱联用法同时测定酒石酸、丙二酸、苹果酸、乳酸、琥珀酸、戊二酸和谷氨酸的方法。研究了电泳条件和质谱条件对有机酸分离的影响。以50.0mmol/L醋酸铵(用1.0mol/L醋酸调至pH4.5)为缓冲溶液,30%异丙醇(含1.0mmol/L氨水)作为鞘液,以保留时间和质荷比对分离出的组分予以定性确证,用峰面积进行定量。结果表明,酒石酸、丙二酸、苹果酸、乳酸、琥珀酸、戊二酸和谷氨酸的线性范围分别为1.0～100.0,4.0～200.0,1.0～100.0,4.0～200.0,2.0～160.0,1.0～80.0和1.0～80.0mg/L;相对偏差均小于8.5%;检出限分别为0.3,1.0,0.3,1.0,0.5,0.3,0.3mg/L。该法用于糖蜜酒精废液中有机酸的测定,结果令人满意。

Determination of Organic Acids in Cane Vinasse by Capillary Electrophoresis-mass Spectrometry

A HPCE-MS method for analyzing tartaric, malonic, malic, lactic, succinic, glutaric and glutamic acid in cane vinasse was established. The influence of both electrophoretic parameters and mass spectrometric parameters on separation of organic acids was investigated. The running buffer was composed of 50.0 mmol/L ammonium acetate (pH was adjusted to 4.5 with 1.0 mmol/L acetic acid). The best sensitivity was obtained with the sheath liquid (1.0 mmol/L ammonia in water/isopropanol (70/30,v/v) solution). The organic acids were identified by retention time and m/z and quantified by peak area. The results demonstrated that the linear ranges were 1.0～100.0, 4.0～200.0, 1.0～100.0, 4.0～200.0, 2.0～160.0, 1.0～80.0, 1.0～80.0 mg/L, with detection limits of 0.3,1.0,0.3, 1.0, 0.5, 0.3,0.3mg/L for tartaric, malonic, malic, lactic,succinic, glutaric and glutamic acid, respectively. The method was applied to determine the organic acids of cane vinasse with satisfactory results.