铬天青S–盐酸氯丙嗪–溴化十六烷基三甲铵光度法测定水样中的铁

Determination of Iron in Water with Chromeazurol S and Chlorpromazine in the Presence of Cetyltrimethylammonium Bromide by Spectrophotometry

采用铁(Ⅲ)–铬天青S–盐酸氯丙嗪–溴化十六烷基三甲铵(CTMAB)四元配合物光度法测定水样中铁的含量。在pH 5.50的HAc–NaAc缓冲介质中,在铁(Ⅲ)–铬天青S–盐酸氯丙嗪显色反应中,加入CTMAB,四元配合物的表观摩尔吸光系数为9.85×10~4 L/(mol·cm),是三元配合物灵敏度的两倍。结果表明,配合物在657nm波长处有最大吸收,Fe(Ⅲ)的质量浓度在0~20μg/(25 mL)范围内与吸光度呈良好的线性关系,线性相关系数为0.999 6,方法的检出限为1.84×10^(–3) mg/L。样品加标回收率为97.3%~98.8%,测定结果的相对标准偏差为1.9%~3.2%(n=5)。该方法灵敏度高,精密度与准确度好,便于在实验室推广应用。

Spectrometry was applied to the determineation of iron in water with Fe（ Ⅲ ）–chromeazurolS–chlorpromazine–cetyltrimethylammonium bromide（CTMAB） quarte–rnary complex. In pH 5.5 buffer solution of HAc–NaAc,CTMAB was added in chromogenic reaction of Fe（ Ⅲ ）–chromeazurol S–chlorpromazine,quarternary complexeof apparent molar absorptivity was 9.85×10^4 L/（mol · cm）,it was twice the sensitivity of the ternary complexes. Theresults showed that the mass concentration of Fe （ Ⅲ ） and absorbance had good linear relationship in the rang of 0–20μg/（25 mL） with the linear correlation coefficient of 0.999 6, the detection limit was 1.84×10^–3 mg/L. The recoverieswere 97.3%–98.8%,and the relative standard deviation of determination results was 1.9%–3.2%（n=5）. The method is easyto be promoted application in the laboratory with high sensitivity,good precision and accuracy.