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本文报导了一种选择性好、灵敏度高的测量水体中亚硝酸盐的新方法——原子吸收间接测定法。方法是NO_2~-在酸性介质中与间苯二酚反应生成4-亚硝基间苯二酚,后者与Pd~(2+)进一步反应生成稳定的螯合物,经甲基异丁基酮萃取,分去水相,有机相吸入乙炔-空气火焰中,通过测定pd~(2+)的含量来间接测定NO_2~-的量。本法对NO_2~-的测定范围为0.04～1.0μg/ml,检出限为0.02μg/ml,NO_2~-的含量为0.2μg/ml的八次测定的变异系数为2.5%。30种异离子及有机物不干扰测定。对四种水样实测结果回收率在95～103%之间,变异系数在3.1%之内,适用于天然水、废水及浅色水样中亚硝酸盐的测定,结果令人满意。
This paper reports a new method for the determination of nitrite in water with good selectivity and sensitivity - indirect atomic absorption spectrometry. The method is that NO2 ~ - reacts with resorcinol in acidic medium to generate 4-nitroso resorcinol, and the latter reacts with Pd ~ (2+) to form a stable chelate. After the reaction, methyl isobutyl The ketone was extracted, the aqueous phase was separated, the organic phase was drawn into the acetylene-air flame, and the amount of NO 2 - was measured indirectly by measuring the content of pd 2+. The determination of NO_2 ~ - in this method is 0.04 ~ 1.0μg / ml, the detection limit is 0.02μg / ml, and the coefficient of variation (CV) is 2.5% for the eight determinations with NO_2 ~ - of 0.2μg / ml. 30 different ions and organic matter does not interfere with the determination. The recoveries of the four water samples were between 95% and 103%, and the coefficients of variation were within 3.1%. The results were satisfactory for the determination of nitrite in natural water, wastewater and light-colored water samples.