电位滴定法测定葡萄酒中的抗坏血酸
Determination of ascorbic acid in wines by automatic potentiometric titration
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摘要: 研究电位滴定法对葡萄酒中抗坏血酸的测定效果,并与化学滴定法进行比较。研究白葡萄酒和红葡萄酒样品中的抗坏血酸测定方法,分别进行线性、重复性、重现性及加标回收实验。结果表明:电位滴定法可直接用于白、红葡萄酒的抗坏血酸测定,线性范围为0.01~0.30 g/L(r=0.9999),精密度<0.3%,重现性<3%,添加回收率为98.0%~99.6%,与国标规定的化学滴定法的测定结果无显著差异(α=0.05)。可见,使用电位滴定法测定葡萄酒中抗坏血酸,线性、精密度和重复性均满足要求,且操作简便、无需脱色处理,有较好的可行性和实用性。Abstract: The determination of ascorbic acid in wines used automatic potentiometric titration was investigated and compared with chemical titration method. The linearity, repeatability, reproducibility and recovery of the determination method were studied.The results showed that the potentiometric titration method was used to determine ascorbic acid in white and red wines directly.The linear range was 0.010.30 g/L ( r = 0.9997) . The RSD value of repeatability and reproducibility were less than 0.3%.The recoveries in the range was 98.0% to 99.6%. And there was no significant difference ( α = 0.05) in measurement values between potentiometric titration method and national standard method. This study suggested that the potentiometric titration method had good linearity, repeatability and reproducibility, which was easy to operate without decoloring treatment. It would be feasible and practicable in determining ascorbic acid in wines.