酚试剂分光光度法测定水中微量戊二醛
Determination of Trace Glutaraldehyde in Water by Spectrophotometric Method with Phenol Reagent
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摘要:
目的 建立一种快速有效地检测水中微量戊二醛的酚试剂分光光度法。 方法 采用戊二醛与酚试剂(3-甲基-苯并噻唑腙,MBTH)反应生成嗪,嗪在酸性溶液中能够被高铁离子氧化生成蓝绿色化合物,利用产生的颜色与戊二醛含量成正比的原理,采用酚试剂分光光度法对水中微量戊二醛含量进行测定,分析入射波长、酚试剂浓度、显色剂酸溶解条件、显色温度和显色时间等因素对实验结果的影响并确定最佳条件。 结果 确定了604 nm处为最佳吸收波长;MBTH和硫酸高铁铵的最佳用量分别为200 mg/L和1 800 mg/L;在30℃下放置15 min后MBTH与戊二醛能够充分反应生成嗪;其次研究了显色剂酸溶解条件,其最佳盐酸溶解用量为0.2 mol/L;最后研究得出最佳显色温度和显色时间为40℃下静置40 min。在最佳测试条件下,吸光度与戊二醛浓度在0.005~1.00 mg/L范围内呈现良好线性关系,检测限为0.005 mg/L,相对标准偏差为0.34%,平均加标回收率为98.13%。 结论 该方法检测限低、灵敏度高、线性范围宽,能够快速有效地检测水中微量戊二醛。 Abstract:Objective To develop a quick and accurate method to determine trace glutaraldehyde in water. Methods Glutaraldehyde reacted with phenol reagent (3-methyl-2-benzothiazolinone hydrazone hydrochloride, MBTH) and produced azine. Azine was oxidized by ferric ions in acid solution to blue-green compounds. A colorimetric assay was conducted because the color of the compound was directly proportional to glutaraldehyde content. The effect of wavelength, phenol reagent concentration, hydrochloric acid, developing temperature, and developing time on the result of test were analyzed, and opt conditions were determined. Results The optimum absorption wavelength was 604 nm; the optimum dosages of MBTH and ammonium ferric sulfate were 200mg/L and 1800mg/L, respectively. Maintaining 30℃ for 15min, MBTH fully reacted with glutaraldehyde and produced azine. The optimum amount of hydrochloric acid as a colorant's solvent was 0.2 mol/L. The optimum developing temperature and time was 40℃ and 40 min respectively, without disturbing. Under the optimal experimental conditions, the absorbance showed an excellent linear relationship with glutaraldehyde in the range of 0.005-1.00 mg/L, and the detection limit was 0.005 mg/L. The relative standard deviation was 0.34%, and the average recovery was 98.13%. Conclusion The described method can quickly determine trace glutaraldehyde in water with low limit of detection, high sensitivity and wide linear range, and thus has the potential in practical application.
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