Shariati-Rad Masoud, Irandoust Mohsen, Mohammadi Shabnam
Department of Analytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran.
Department of Analytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran.
Spectrochim Acta A Mol Biomol Spectrosc. 2015;149:190-5. doi: 10.1016/j.saa.2015.04.083. Epub 2015 May 2.
The present paper seeks to develop a simple method for the spectrophotometric determination of nitrite in soil and water samples and also measure optimum reaction conditions along with other analytical parameters. The method is based on the diazotization-coupling reaction of nitrite with cefixime and 1-naphthylamine in an acidic solution (Griess reaction). The final product that is an azo dye has an orange color with maximum absorption at 360 nm which Beer's Law is obeyed over the concentration range 0.02-15.00 mg L(-1) of nitrite. Optimal conditions of the variables affecting the reaction were obtained by central composite design (CCD). A detection limit of 4.3×10(-3) mg L(-1) was obtained for determination of nitrite by the proposed method. The proposed method was successfully applied to determine nitrite in soil and water samples. The molar absorptivity of the product of the reaction and RSD in determination of nitrite in real samples are 4.1×10(3) (L mol(-1) cm(-1)) and lower than 10%, respectively.
本文旨在开发一种用于分光光度法测定土壤和水样中亚硝酸盐的简单方法，并测定最佳反应条件以及其他分析参数。该方法基于亚硝酸盐在酸性溶液中与头孢克肟和1-萘胺的重氮化偶联反应（格里斯反应）。最终产物即偶氮染料呈橙色，在360 nm处有最大吸收，在0.02 - 15.00 mg L(-1)的亚硝酸盐浓度范围内符合比尔定律。通过中心复合设计（CCD）获得了影响反应的变量的最佳条件。所提出的方法测定亚硝酸盐的检出限为4.3×10(-3) mg L(-1)。该方法成功应用于测定土壤和水样中的亚硝酸盐。反应产物的摩尔吸光系数以及实际样品中亚硝酸盐测定的相对标准偏差分别为4.1×10(3)（L mol(-1) cm(-1)）和低于10%。
