Gómez-Alvarez E, Luque-Pérez E, Rı X0301 Os A, Valcárcel M
Department of Analytical Chemistry, Faculty of Sciences. University of Córdoba, E-14004 Córdoba, Spain.
Talanta. 1999 Aug 23;50(1):121-31. doi: 10.1016/s0039-9140(99)00112-5.
A spectrophotometric method for the determination of lactic acid in milk samples based on the use of a photochemical reaction carried out in a Flow Injection System is proposed. Determination is based on the reaction between lactic acid and Fe(III), which is reduced to Fe(II) in the presence of UV light, being the latter made to react with o-phenanthroline. The complex formed between Fe(II) and o-phenanthroline, Fe(o-phen)(3)(2+) (ferroin) is a coloured compound and it can be spectrophotometrically monitored at 512 nm. The method shows a linear range between 0.5 and 50 mug ml(-1) with a limit of detection of 0.16 mug ml(-1). The precision was +/-2.15 expressed as relative standard deviation (n=11) and the sample throughput of 30 samples h(-1). Also non-linear adjustments have been made and validated by ANOVA. The proposed method has been applied to the determination of lactic acid in both synthetic and milk samples.
提出了一种基于流动注射系统中光化学反应测定牛奶样品中乳酸的分光光度法。测定基于乳酸与Fe(III)之间的反应，在紫外光存在下Fe(III)被还原为Fe(II)，然后使Fe(II)与邻菲啰啉反应。Fe(II)与邻菲啰啉形成的配合物Fe(o-phen)(3)(2+)（亚铁菲啰啉）是一种有色化合物，可在512 nm处进行分光光度监测。该方法的线性范围为0.5至50 μg ml(-1)，检测限为0.16 μg ml(-1)。以相对标准偏差表示的精密度为±2.15（n = 11），样品通量为30个样品 h(-1)。还进行了非线性调整并通过方差分析进行了验证。所提出的方法已应用于合成样品和牛奶样品中乳酸的测定。
