微波消解-火焰原子吸收光谱法测定冷轧碱性脱脂剂中钙、镁的含量  

Determination of calcium and magnesium contents in alkaline degreaser for cold rolling by flame atomicabsorption spectrometry with microwave digestion

作　　者：董礼男 张继明 赵希文 朱春要 DONG Li’nan;ZHANG Jiming;ZHAO Xiwen;ZHU Chunyao(Institute of Research of Iron and Steel,Jiangsu Province/Sha-Steel,Zhangjiagang 215625,China)

机构地区：[1]江苏省(沙钢)钢铁研究院,江苏张家港215625

出　　处：《电镀与涂饰》2023年第16期71-76,共6页Electroplating & Finishing

摘　　要：在样品中加入硝酸和氢氟酸后,置于微波消解仪中进行前处理以除去其中的有机物与硅酸盐,选择Ca422.7 nm和Mg 285.2 nm作为分析谱线,建立了火焰原子吸收光谱法测定冷轧退火前用碱性脱脂剂中钙、镁含量的方法。讨论了样品的前处理方式及酸介质的浓度,考察了共存元素对钙、镁元素测定的影响。确定5 mL样品中加入8 mL硝酸和2 mL氢氟酸作为消解液,消解后的待测液在体积分数为15%的盐酸介质中进行仪器检测,采用氯化锶作为释放剂以消除硅对测定钙的影响。结果表明:在最佳仪器工作条件下,钙、镁元素校准曲线的线性相关系数分别为0.999 6和0.999 8,检出限分别为0.130 mg/L和0.066 mg/L。按照本法测定生产现场的冷轧碱性脱脂剂中钙、镁元素含量,检测结果的相对标准偏差(RSD,n=11)小于2.00%,加标回收率在96.50%~103.5%之间。A method for determination of Ca and Mg in the alkaline degreaser used prior to annealing during the cold rolling process was established based on flame atomic absorption spectrometry(FAAS).The sample was mixed with nitric acid and hydrofluoric acid,and then digested by microwave to eliminate the interference of organic matters and silicate.Ca was determined at a wavelength of 422.7 nm and Mg at 285.2 nm.The pretreatment of sample and the acid concentration of medium were discussed.The effects of coexisting elements on the determination were studied.It is recommended that the sample of 5 mL should be pretreated by microwave digestion in a mixture of nitric acid 8 mL and hydrofluoric acid 2 mL,and then analyzed by FAAS in a medium of 15%(volume fraction)hydrochloric acid with strontium chloride as a releasing agent to eliminate the influence of the coexisting silicon on the determination of calcium.Under the optimized working conditions,the linear correlation coefficient of calibration curve was 0.9996 for Ca and 0.9998 for Mg,and the detection limit was 0.130 mg/L for Ca and 0.066 mg/L for Mg.The relative standard deviations(RSD,n=11)for determination of Ca and Mg contents in the alkaline degreaser sampled from a cold rolling plant were less than 2.00%,and the spike recoveries were between 96.50%and 103.5%.

关 键 词：冷轧 碱性脱脂剂 微波消解 钙 镁 火焰原子吸收光谱法 

分 类 号：O657.31[理学—分析化学]