粮食及其制品中合成着色剂检测方法的改进

以甲醇-氨水-水作为提取液,对绿豆、小米、紫米等有色粮食及方便面、挂面等粮食制品中的色素进行提取,提取液经过浓缩、定容和过滤后进行高效液相色谱测定,以甲醇和0.02 mol.L-1乙酸铵溶液进行梯度洗脱,采用多波长(4284,822,54,5106,00 nm)同时测定提取液中的柠檬黄、日落黄、胭脂红、苋菜红、亮蓝.结果表明,该法对柠檬黄、日落黄、胭脂红、苋菜红和亮蓝的检出限分别为1.01,1.70,4.38,1.14,5.32 ng,平均回收率达到82%～102%,相对标准偏差为0.6%～5.3%.该方法操作简单,节省时间,同时采用多波长测定方法减少了其他组分的干扰,提高了测定的灵敏度.

Improvement of Testing Method of Synthetic Colors in Cereals and Their Products

Pigments in cereal products including mung bean,millet,purple rice,fine dried noodles and instant noodles were extracted using methanol-ammonia-water as the solvent.High performance liquid chromatography(HPLC) was used to determine the concentration of tartrazine,sunset yellow,carmine,amaranth,and brilliant blue in the extracts simultaneously by the multi-wavelength(428,482,254,510 nm,and 600 nm) method,using methanol and 0.02 mol·L-1 ammonium acetate as the gradient elution.The results showed that the detection limits of tartrazine,sunset yellow,carmine,amaranth,and brilliant blue were 1.01,1.70,4.38,1.14 ng,and 5.32 ng,respectively,the average recovery was around 82%～102%,and the relative standard deviation(RSD) was 0.6%～5.3%.This method is simple,time-saving,and the sensitivity is improved for the multi-wavelength treatment reduces the disturbance of other components.