抑制氧化甲基橙光度法测定贝类中牛磺酸

Spectrophotometric Determination of Taurine in Shellfish by Inhibiting Methyl Orange Oxidation

摘要:

本研究建立了分光光度法测定贝类中牛磺酸的新方法。痕量牛磺酸在pH 11.0氨-氯化铵缓冲液中对高锰酸钾氧化甲基橙的反应具有显著抑制作用，使体系褪色，吸光度明显减小。试验了酸度、高锰酸钾用量、甲基橙用量、温度和时间的影响，确定了最佳反应条件。在最佳反应条件下，最大褪色波长位于690 nm，吸光度减小值与牛磺酸质量浓度在0~75 μg/L范围内呈良好的线性关系，表观摩尔吸光系数为2.22×106 L/(mol?cm)，检出限为1.19 μg/L。采用热水浸提和离子交换法处理样品，将该方法用于测定文蛤、缢蛏、栉孔扇贝和四角蛤蜊中牛磺酸，结果与高效液相色谱法一致，相对标准偏差为0.82~1.24%（n=6），回收率为98.31~101.76%。该方法灵敏、准确、简便、快速、精密度高，选择性好，反应条件温和，对环境友好，适用于贝类中牛磺酸的测定。

Abstract:

Trace taurine has obvious inhibitory effect on the reaction of potassium hypermanganate oxidizing methyl orange in ammonium chloride-ammonia buffer solution at pH 11.0, resulting in fading of the system and great decrease of absorbance. The acidity, potassium hypermanganate and methyl orange dosage, temperature and time were optimized. Under the optimum reaction conditions, good linear relationship was obtained between the decreased value of absorbance and taurine concentration in the range of 0~75 μg/L with the maximum fading wavelength of 690 nm. The apparent molar absorption coefficient was 2.22×106 L/(mol?cm), with detection limit of 1.19 μg/L. Samples were pretreated using hot water extraction and ion exchange , the proposed method was applied to the determination of taurine in Meretrix meretrix, Sinonovacula constricta, Chlamys farreri and Mactra veneriformis. The results agreed well with those obtained by high performance liquid chromatography. The relative standard deviation was 0.82~1.24% (n = 6), and recovery was 98.31~101.76%. This method was sensitive, accurate, simple, rapid and environmentally friendly under, which was suitable for determination of taurine in shellfish.