三种不同方法测定室内空气中甲醛含量的比较

Comparison of Three Different Methods for Determining the Formaldehyde Content in Indoor Air

目的:用酚试剂分光光度法、乙酰丙酮分光光度法和4-氨基-3-联氨-5-巯基-1,2,4-三氮杂茂(AHMT)分光光度法三种方法测定空气中甲醛,通过比较测得的甲醛数据,找出3种方法优劣。方法:用5mL蒸馏水作为吸收液采样空气样,取(1~5)mL样量按三种方法分别检测出5mL吸收液中甲醛量,再除以采样体积,计算出空气中甲醛浓度。结果:三种方法线性关系良好,相关系数均大于0.9990,BY400160标准水样用三种方法测定的甲醛结果为酚试剂法1.49mg/L,乙酰丙酮法1.50mg/L,AHMT法1.51mg/L,标准水样参考值(1.49±0.07)mg/L。三种方法的相对标准偏差:酚试剂分光光主法(2.23~3.83)%,乙酰丙酮分光度法(1.64~2.84)%,AHMT分光光度法(3.80~4.36)%。结论:三种方法的线性宽、灵敏度好、检出限低、精密度和准确度令人满意,能精准测定室内空气中甲醛。

Objective: Phenol reagent spectrophotometry, acetylacetone spectrophotometry and 4-amino-3-hydrazine-5-mercapto-1,2,4-triazacene(AHMT) spectrophotometry were used to determine formaldehyde in the air, and the measured formaldehyde data was compared to find out pros and cons of three methods.Methods:Use 5 mL of distilled water as the absorption solution to collect air samples, take(1~5)mL of the sample solution to detect the amount of formaldehyde in the 5 mL absorption solution according to three methods, and divide by the sampling volume to calculate the concentration of formaldehyde in the air.Results:Three methods have good linearity and the correlation coefficient are all larger than 0.9990.Formaldehyde results of BY400160 standard samples measured by three methods: phenol reagent method 1.49 mg/L, acetylacetone method 1.50 mg/L, AHMT method 1.51 mg/L, reference value of standard sample(1.49±0.07)mg/L.Relative standard deviation(RSD) of three methods: phenol reagent method(2.23~3.83)%, acetylacetone method(1.64~2.84)%, AHMT method(3.80~4.36)%.Conclusion:The three methods have wide linearity, good sensitivity, low detection limit, satisfactory precision and accuracy, and can accurately determine formaldehyde content in indoor air.