Gu Chang-Yu, Li Xiao-Bin, Chai Xiao, Wang Zhen, Hou Chen-Yu, Ke Run-Hui
Sinolight Inspection & Certification Co., Ltd., Beijing 100016, China.
China National Research Institute of Food & Fermentation Industries Co., Ltd., Beijing 100015, China.
Se Pu. 2024 Aug;42(8):792-798. doi: 10.3724/SP.J.1123.2023.10016.
Sodium cyclamate in Baijiu is a key item in the China National Food Safety Supervision and Inspection Plan. A simple, economical, sensitive, and reliable method is urgently needed for routine analysis and internal quality control. A method based on high performance liquid chromatography with fluorescence detection (HPLC-FLD) was developed for the determination of sodium cyclamate in Baijiu by -phthalaldehyde derivatization. First, the sodium cyclamate in the sample solution was converted into amino compounds using the desulfurization reaction under acidic conditions. Next, 400 g/L sodium hydroxide solution was added to the sample solution for neutralization. The amino compounds in the sample solution were then derivatized with -phthalaldehyde to produce indole-substituted derivatives that are capable of producing fluorescence signals. Separation was carried out on a C18 column (250 mm×4.6 mm, 5 μm) in isocratic elution mode using a mobile phase consisting of acetonitrile and phosphate buffer. Finally, the eluate was monitored using a fluorescence detector, and an external standard method was used for quantification. A good linear relationship was obtained in the range of 0.1-2.0 mg/L, with correlation coefficients greater than 0.999. The average recoveries of sodium cyclamate spiked at levels of 0.1-1.0 mg/kg in Baijiu samples ranged from 90.7% to 100.9%, with relative standard deviations (RSDs) of 3.5%-5.6% (=6). The limits of detection and quantification were 0.03 and 0.10 mg/kg, respectively. Nine Baijiu samples collected from the market were tested, and the results demonstrated that the contents of sodium cyclamate detected by the developed method were consistent with those obtained using the liquid chromatography-tandem mass spectrometry (LC-MS/MS) method described in GB 5009.97-2016 (the third method). The proposed method is economical, sensitive, specific, and accurate; thus, it provides a basic approach for the determination of sodium cyclamate in Baijiu samples and has great potential for routine analysis in foodstuffs.
白酒中的甜蜜素是中国国家食品安全监督抽检计划中的重点项目。迫切需要一种简单、经济、灵敏且可靠的方法用于常规分析和内部质量控制。建立了一种基于高效液相色谱-荧光检测法（HPLC-FLD）的方法，通过邻苯二甲醛衍生化来测定白酒中的甜蜜素。首先，在酸性条件下利用脱硫反应将样品溶液中的甜蜜素转化为氨基化合物。接着，向样品溶液中加入400 g/L氢氧化钠溶液进行中和。然后，样品溶液中的氨基化合物用邻苯二甲醛进行衍生化，生成能够产生荧光信号的吲哚取代衍生物。采用等度洗脱模式，在C18柱（250 mm×4.6 mm，5 μm）上进行分离，流动相由乙腈和磷酸盐缓冲液组成。最后，使用荧光检测器对洗脱液进行监测，并采用外标法进行定量。在0.1 - 2.0 mg/L范围内获得了良好的线性关系，相关系数大于0.999。白酒样品中添加水平为0.1 - 1.0 mg/kg的甜蜜素平均回收率为90.7%至100.9%，相对标准偏差（RSD）为3.5% - 5.6%（n = 6）。检测限和定量限分别为0.03和0.10 mg/kg。对从市场上采集的9个白酒样品进行了检测，结果表明，所建立方法检测出的甜蜜素含量与采用GB 5009.97 - 2016中描述的液相色谱-串联质谱法（LC-MS/MS）（第三法）获得的结果一致。所提出的方法经济、灵敏、特异且准确；因此，它为白酒样品中甜蜜素的测定提供了一种基本方法，在食品常规分析中具有很大潜力。
