利用超高效液相色谱-质谱联用(UPLC-MS)技术,建立了发酵乳中乙酸,乳酸,琥珀酸的检测方法.色谱条件为:采用ACQUITY UPlC HSS T3色谱柱进行分离,乙腈-0.1％甲酸/1 mmol/L甲酸铵水溶液体系作为流动相进行梯度洗脱,流速为0.25 mL/min,柱温为30℃,进样量5μL.质谱采集选择ESI-负离子监测模式进行扫描,优化锥孔电压和碰撞能量等质谱条件,离子源温度100℃,脱溶剂气温度450℃,脱溶剂气流量600 L/h.通过绘制有机酸的标准曲线,得到乙酸、琥珀酸、乳酸的线性范围分别是0～100,0～80,0～600 μg/mL;最低检出限分别为0.04,0.0025,0.0025 μg/mL;最低定量限分别为0.2,0.01,0.01 μg/mL;相关系数范围R2为0.9951～0.9997,回收率范围为93.5％～106.07％.该方法准确、快速,可用于检测发酵乳中有机酸的含量.%This study established a method for detecting the three kinds of short-chain fatty acids,acetic acid,lactic acid,and succinic acid of the fermented milk by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS).Chromatographic conditions were as follows:the ACQUITY UPLC HSS T3 was used to separate the organic acids,acetonitrile solution-0.1％ formic acid/1 mmol/L ammonium formate aqueous solution as mobile phase to gradient elute the sample,the flow rate was 0.25 mL/min,column temperature was set to 30 ℃,the injection volumn was 5 μL.The ESI-negative mode was selected to monitor the changes,in addition,the cone voltage and collision energy were optimized to obtain an appropriate method,the operating conditions were as follows:source temperature 100 ℃,desolvation temperature 450 ℃,desolvation gas flow 600 L/h,cone gas flow 50 L/h.By drawing the standard curve of organic acid,the linear range of acetic acid,lactic acid and succinic acid were ensured as follows:0～100,0～80,0～600 μg/mL respectively;the minimum detection limits were 0.04,0.0025 and 0.0025 μg/mL;the minimum quantitative limits were 0.2,0.01,0.01 μg/mL;the range of correlation coefficient R2 was between 0.9951～).9997,and the recoveries varied between 81.3％～102.2％.The established method was proved to be accurate and fast for the determination of organic acids in fermented milk.
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