酸碱滴定法测定戊二醛含量影响因素的研究

STUDY ON FACTORS INFLUENCING MEASUREMENT OF GLUTARALDEHYDE CONTENT BY ACID-BASE TITRATION METHOD

目的探讨酸碱滴定法测定戊二醛含量的影响因素。方法采用羟胺法检测戊二醛原液稀释度、不同取样量、反应时间以及其它化合物对戊二醛测定准确度的影响。结果将含量为550g/L的戊二醛用标准硬水稀释2倍和25倍,3组戊二醛含量测定结果的相对误差均<3%。测定中,戊二醛实际取样量在0.180g和0.220g范围,对戊二醛含量测定基本没有影响;取样量≤0.150g或≥0.250g,都会明显影响戊二醛含量测定结果。测定加样反应时间在55min^65min之间,对测定结果基本无影响;反应时间短于55min或长于65min都对测定结果产生明显影响。在戊二醛消毒液中含有甲醛与乙二醛等醛类杂质可造成戊二醛含量测定值增加。结论采用羟胺法测定消毒液戊二醛含量,每份戊二醛取样量应为0.180~0.220g,加样后反应时间应为55~65min;该方法不适合含有甲醛、乙二醛等醛类杂质的消毒剂样品中戊二醛含量的测定。

Objective To explore the factors influencing measurement of glutaraldehyde content by acid - base titration method. Methods Hydoxy amine method was used to measure the dilution of glutaraldehyde stock solution, different amounts of sample taken and reaction time and examine the influence of other compounds on accuracy of measurement of glutaraldehyde. Results After 550 g/L glutaraldehyde was dituted by 2 times and 25 times with standard hard water, the relative error of measured results of glutaraldehyde content of all the 3 groups was 〈3%. The actual amount of glutaraldehyde taken for measurement in the range of 0. 180 g to 0.220 g essentially did not influence the measurement of glutaraldehyde content, while the amount ≤0. 150 g or≥250 g influenced obviously on the measured result of glutaraldehyde con- tent. The reaction time between 55 to 65 rain after adding the sample essentially did not influence the measured results, while the reaction time shorter than 55 rain or longer than 65 rain significantly influenced the measured results. Aldehyde impurities such as formaldehyde and glyoxal in glutaraldehyde disinfection solution could cause increase in measured value of glutaraldehyde. Conclusion When hydroxy amine method is used for measuring glutaraldehyde content of disinfection solution, each sample of glutaraldehyde taken should be 0. 180 -0. 220 g. The reaction time after adding sample should be 55 - 65 min. This method is unsuitable for measuring glutaraldehyde content in the disinfectant sample containing aldehyde impurities such as formaldehyde and glyoxal.