Horie Masao, Ishikawa Fusako, Oishi Mitsuo, Shindo Tetsuya, Yasui Akiko, Ito Koichi
Department of Food Safety, Tokyo Metropolitan Institute of Public Health, 3-24-1 Hyakunin-cho, Shinjuku-ku, Tokyo 169-0073, Japan.
J Chromatogr A. 2007 Jun 22;1154(1-2):423-8. doi: 10.1016/j.chroma.2007.03.094. Epub 2007 Mar 30.
A method for the determination of cyclamate in food was developed using solid-phase extraction (SPE) and capillary electrophoresis (CE) with indirect ultraviolet (UV) detection. A 5-10 g sample in 0.1 mol/L hydrochloric acid was homogenized and made up to a volume of 50 mL with 0.1 mol/L hydrochloric acid. After the sample was centrifuged, 25 mL of supernatant was loaded into an Oasis HLB SPE cartridge. The cartridge was washed with 2 mL of demineralized water followed by 2 mL of 50% aqueous methanol, and cyclamate was eluted with 4.5 mL of 50% aqueous methanol. The eluate was added to a solution of sodium propionate (internal standard) for CE analysis. The cyclamate in the eluate was electrophoresed on a fused-silica capillary using 1 mmol/L hexadecyltrimethylammonium bromide and 10 mmol/L potassium sorbate as a running buffer. Detection and reference wavelengths of cyclamate determined with a UV detector were 300 and 254 nm, respectively. The calibration curves for cyclamate showed good linearity in the range of 2-1000 microg/mL and the limits of detection in beverage, fruit in syrup, jam, pickles and confectionary are sample dependent and ranged from 5-10 microg/g. The recovery of cyclamate added at a level of 200 microg/g to various kinds of foods was 93.3-108.3% and the relative standard deviation was less than 4.9% (n=3). A number of commercial samples were analyzed using the proposed method. Cyclamate was detected in one waume, two pickles, and two sunflower seeds. The quantitative values determined with CE correlated to those from high-performance liquid chromatography (HPLC) (the detected values of cyclamate in a sunflower seed measured by CE and HPLC were 3.40 g/kg and 3.51 g/kg, respectively). This analytical method for cyclamate using CE is especially suitable for use in the field.
建立了一种采用固相萃取（SPE）和毛细管电泳（CE）结合间接紫外（UV）检测法测定食品中环己基氨基磺酸钠的方法。将5 - 10 g样品置于0.1 mol/L盐酸中匀浆，并用0.1 mol/L盐酸定容至50 mL。样品离心后，取25 mL上清液加载到Oasis HLB固相萃取柱中。先用2 mL去离子水冲洗柱子，再用2 mL 50%甲醇水溶液冲洗，然后用4.5 mL 50%甲醇水溶液洗脱环己基氨基磺酸钠。将洗脱液加入丙酸钠溶液（内标）中进行毛细管电泳分析。在熔融石英毛细管上，以1 mmol/L十六烷基三甲基溴化铵和10 mmol/L山梨酸钾作为运行缓冲液对洗脱液中的环己基氨基磺酸钠进行电泳。用紫外检测器测定环己基氨基磺酸钠的检测波长和参比波长分别为300 nm和254 nm。环己基氨基磺酸钠的校准曲线在2 - 1000 μg/mL范围内呈良好线性，饮料、糖浆水果、果酱、泡菜和糖果中的检测限因样品而异，范围为5 - 10 μg/g。向各类食品中添加200 μg/g的环己基氨基磺酸钠，回收率为93.3% - 108.3%，相对标准偏差小于4.9%（n = 3）。使用该方法分析了多个商业样品。在一个饮料、两个泡菜和两个葵花籽样品中检测到了环己基氨基磺酸钠。毛细管电泳测定的定量值与高效液相色谱（HPLC）测定的结果相关（通过毛细管电泳和高效液相色谱测定的一个葵花籽样品中环己基氨基磺酸钠的检测值分别为3.40 g/kg和3.51 g/kg）。这种采用毛细管电泳测定环己基氨基磺酸钠的分析方法特别适用于现场检测。
