硫酸钡比浊法测定食盐中钡含量的优化

目的优化硫酸钡比浊法测定食盐中钡含量的分析方法。方法采用紫外分光光度计对样品悬浊液进行光度测试,分别探讨了测定波长、稳定剂加入量、静置时间对硫酸钡悬浊液体系的影响。结果优化后的方法为:待测溶液加入5 mL甘油-乙醇稳定剂静置10 min后,在波长420 nm处进行测定,标准曲线在钡含量0～3mg范围,相关系数r~2达到0.99915,线性良好,实际检测样品的相对标准偏差在0.71%～4.3%之间,回收率大于90%。结论用分光光度法测定食盐中的钡含量解决了GB5009.42-2016比浊法无法定量测定的缺陷,对进一步监测食盐中的钡提供了帮助,该检测方法可满足食盐中钡含量的定量测定要求。

Optimization of barium in edible salt by barium sulfate turbidimetric method

Objective To optimize the method for the determination of barium in edible salt by barium sulfate turbidimetric method. Methods Through testing absorbance of sample suspension by UV-visible spectroscopy, the effects of wavelength, stabilizer addition amount and reaction time on the system of barium sulfate suspension were discussed. Results The optimized method was as follows: added 5 mL glycerin ethanol stabilizer to the solution to be tested, and let it stand for 10 min, and then determined it at the wavelength of 420 nm. The standard curve was in the range of barium content 0?3 mg, and the correlation coefficient r2 reached 0.99915. The relative standard deviation of the actual test samples was between 0.71% and 4.3%, and the recovery rate was greater than 90%. Conclusion Using spectrophotometry for determination of bariumin salt can solve GB 5009.42?2016 burbidimetry limited measurement defects, and provides help for further testing the specific content of baium inedible salt. This method is suitable for the quantitative determination of barium in edible salt.