Haghighi B, Tavassoli A
Department of Chemistry, Institute for Advanced Studies in Basic Sciences, Gava Zang, PO Box 45195-159, Zanjan, Iran.
Talanta. 2002 Jan 4;56(1):137-44. doi: 10.1016/s0039-9140(01)00548-3.
A flow injection method on the basis of gas phase molecular absorption is described for the determination of nitrite in the aqueous solution. 200 mul of nitrite solution is introduced into a carrier stream of distilled water. The carrier stream containing nitrite zone is reacted with a stream of hydrochloric acid (2 M). The stream is then segmented by O(2) gas. The produced gaseous products are purged into the O(2) segments, react with O(2) and are carried toward the gas-liquid separator. The gaseous phase is separated from the liquid stream by the use of home-made gas-liquid separator and then is swept into a home-made flow cell. The absorbance of gaseous phase is measured at 205 nm using a UV/VIS spectrophotometer. Under selected conditions, two linear ranges, up to 1000 mug ml(-1) and 1000-2000 mug ml(-1) of nitrite were obtained. The limit of detection was 7.5 mug ml(-1) NO(2)(-). The relative standard deviations of repeated measurements of 100 and 500 mug ml(-1) NO(2)(-) were 3.7 and 1.0%, respectively. Up to 30 samples h(-1) can be analyzed. Interferences in the proposed method were few and were readily overcome. The proposed method was successfully applied to the determination of nitrite in the spiked water samples, a number of meat products and urine.
描述了一种基于气相分子吸收的流动注射法，用于测定水溶液中的亚硝酸盐。将200微升亚硝酸盐溶液引入蒸馏水流中。含有亚硝酸盐区带的载流与盐酸（2M）流反应。然后用氧气将该流分段。产生的气态产物被吹扫到氧气段中，与氧气反应并被带向气液分离器。使用自制的气液分离器将气相与液流分离，然后将其吹扫到自制的流通池中。使用紫外可见分光光度计在205nm处测量气相的吸光度。在选定条件下，获得了两个线性范围，亚硝酸盐浓度高达1000微克/毫升和1000 - 2000微克/毫升。检测限为7.5微克/毫升亚硝酸根。对100微克/毫升和500微克/毫升亚硝酸根进行重复测量的相对标准偏差分别为3.7%和1.0%。每小时最多可分析30个样品。该方法的干扰很少且易于克服。该方法成功应用于加标水样、多种肉类产品和尿液中亚硝酸盐的测定。
