【摘要】 建立食品中非食用色素罗丹明B的胶束电动毛细管色谱-激光诱导荧光检测方法。以75μm×30 cm（有效长度为20 cm）未涂层熔融石英毛细管为分离柱;以30 mmol/L Na₂B₄O₇+20 mmol/L十二烷基硫酸钠（sodium sodecyl sulfonate,SDS）+20 mmol/L脱氧胆酸钠+0.2 g/L聚乙二醇35000为分离缓冲溶液,10 mmol/L SDS为样品提取液,在10 min内即可实现罗丹明B的测定。分离电压8 kV、进样压力3.448 kPa、时间5 s,激发波长488 nm,发射波长520 nm。检出限和定量限分别为5μg/L和15μg/L。在0.02～1.28 mg/L范围内,罗丹明B的校正峰面积与质量浓度呈良好线性关系,相关系数为0.999 9。方法日内及日间精密度相对标准偏差均不高于2%。低、中和高添加水平（0.04、0.16、0.64 mg/L）的加标回收率在100.9%～105.8%之间。用该方法测定3个番茄酱样品、3个番茄沙司样品和22个辣椒粉样品,胶束电动毛细管色谱-激光诱导荧光法检测结果均比超高效液相色谱-荧光检测法结果偏低,对可能的原因进行了分析。更多还原

【Abstract】 A new and simple method was developed for the accurate determination of rhodamine B in ketchup, tomato sauce and chili powder samples by micellar electrokinetic capillary chromatography（MEKC） with laser-induced fluorescence（LIF） detection. The separation was performed on an uncoated fused silica capillary 75 μm × 30 cm total length（effective length: 20 cm） with a separation buffer solution consisting of 30 mmol/L sodium tetraborate, 20 mmol/L sodium dodecyl sulfonate（SDS）, 20 mmol/L sodium deoxycholate（SD） and 0.2 g/L polyethyleneglycol 35000. A solution containing 10 mmol/L SDS was used for sample extraction. The analysis could be completed within 10 min. A voltage of 8 kV was used for separation. The injection time and pressure were 5 s and 3.448 kPa, respectively. The excitation and emission wavelengths were 488 nm and 520 nm, respectively. The corrected peak area and the concentration of rhodamine B displayed a good linear relationship with a correlation coefficient（r） of 0.999 9 in the ranges of 0.02–1.28 mg/L. The limit of detection(LOD; R_SN = 3) and limit of quantitation(LOQ; R_SN = 10) were 5 and 15 μg/L, respectively. The intra-day and inter-day precisions of the method were both no less than 2%. The average recoveries of rhodamine B at three spiked concentrations（0.04, 0.16 and 0.64 mg/L） were in the ranges of 100.9%–105.8%. When the MEKC method was used to determine the contents of rhodamine B in 3 ketchup, 3 tomato sauce and 22 chili powder samples, the results were all lower than those measured by ultra-high performance liquid chromatography-fluorescence detection（UPLC-FLR）. The possible reasons for the difference were analyzed and discussed.更多还原