摘要:本实验提出了食品中维生素C测定的新方法。该法基于将样品中维生素C经水溶解再与碱性铜盐溶液反应，最后以火焰原子吸收光谱法测定反应后留存在溶液中的铜含量，从而间接求得样品中维生素C的含量。通过单因素和正交实验确定斐林试剂的用量、反应温度、反应时间、离心时间和pH对实验的影响。结果表明，在1.00mL10.00mg/mL的维生素C标准溶液中斐林试剂的用量为2.00mL、室温下反应时间为35min、离心时间为10min和pH为原溶液（12.00～13.16）时为最佳实验条件，可用于实际样品的测定。用间接原子吸收法，其检出限为5.514mg/mL，在最佳条件下对样品测定的相对标准偏差为0.68%～5.56%，加标回收率在90.31%～108.29%之间。其测定结果与国标测定结果相比较，相对误差在0.99%～7.84%之间，结果基本一致。
此方法简便、准确、抗干扰能力强，可作为维生素C的一种快检方法。
关键词 维生素C；火焰原子吸收间接法；铜
Abstract:This paper presents a new method for the determination of vitamin C in food. The method is based on the sample of the vitamin C in the water solution by reacting with alkaline copper salt solution, and finally by the flame atomic absorption spectrometry method for the determination of the copper content in remaining in the sample solution after reaction, thereby to obtain the content of vitamin C in the sample solution indirectly. By single factor and orthogonal experiments determine the Fei Lin liquid dosage, reaction temperature, reaction time, centrifugal time and pH on experimental effects. The results show that, in 1.00mL10.00mg/mL vitamin C standard solution Fei Lin liquid dosage is 2.00mL, the reaction time is 35min in the room temperature, the centrifugal time is 10min and pH as raw solution (12.0~13.16) is the best test condition, and can be used for analysis of real samples. By indirect atomic absorption method, the detection limit of 5.514mg/mL, the optimum conditions for determination of the relative standard deviation is 0.68%~5.56%, and the recovery rate between 90.31% and 108.29%. The determination results of determination results compared with national standard, the relative error is in 0.99%~7.84%, and the results are consistent. This method is simple, accurate, strong anti-interference ability, can be used as a rapid detecting method for vitamin C.
Keywords Vc Indirect flame atomic absorption method Copper
