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建立了氯乙烯滤膜采样,抗坏血酸还原-钼蓝分光光度法测定环境空气中五氧化二磷的方法,确定了测定最佳波长和比色皿规格,比较了反应体系不同的酸度,钼酸铵、抗坏血酸及酒石酸锑钾的试剂用量,显色温度和时间等对方法的影响,同时分别对氯乙烯滤膜、玻璃纤维滤膜和石英滤膜进行了对比,发现氯乙烯滤膜具有较低的本底空白;经条件优化后,标准曲线相关系数为0.9999,当采样体积为5 m3时,方法的检出限和测定下限分别为0.15μg/m3和0.60μg/m3,高低两种浓度的空白滤膜和实际样品加标,方法的精密度均在10%以内,加标回收率在97%~110%之间。分别研究了As,Hg,Cr,Si和氟化物等对方法的干扰和消除,当As含量大于0.2μg/m3,Cr(Ⅵ)含量大于200μg/m3时对方法负干扰,Na SO3溶液和Na2S2O3溶液的混合还原剂可以消除,使用混合还原剂先配制再加入的方法可以在一定程度上消除含硅化合物的正干扰,Hg和氟化物对方法不产生干扰。
A method was established for the determination of phosphorus pentoxide in the ambient air by using VCI membrane sampling and ascorbic acid reduction-molybdenum blue spectrophotometry. The optimal wavelength and cuvette specifications were determined. The different acidities of the reaction system, ammonium molybdate , Ascorbic acid and antimony potassium tartrate reagent dosage, color temperature and time on the method of impact, at the same time, vinyl chloride membrane, glass fiber membrane and quartz filter were compared and found that vinyl chloride membrane has a lower After the optimized conditions, the correlation coefficient of the standard curve is 0.9999. When the sample volume is 5 m3, the detection limit and the lower limit of determination are 0.15μg / m3 and 0.60μg / m3 respectively. The membrane and the actual sample spiked, the precision of the method is less than 10%, the spiked recovery rate is between 97% and 110%. The interference and elimination of As, Hg, Cr, Si and fluoride were studied respectively. Negative interferences were observed when the content of As was more than 0.2μg / m3 and the content of Cr (Ⅵ) was more than 200μg / m3. Mixed reductant solution can be eliminated, the use of mixed reductant first prepared by adding the method can be to some extent eliminate the positive interference of silicon-containing compounds, Hg and fluoride on the method does not cause interference.