摘要
碘是评价环境的重要元素之一,是地球化学勘察样品常测元素。通过考察艾斯卡试剂手工制作与行星球磨机制作的利弊、参比液的选择、17~25℃不同环境温度条件对实验结果的影响,采用全程序空白溶液和36 g/L的碳酸钠溶液两种方法制作标准曲线并得出标准曲线线性范围,同时也考察了样品烧结时间及温度、乙酸用量对样品测试吸光度的影响。建立了艾斯卡试剂分解-热水提取样品,催化分光光度法时间程序测定碘的方法。结果表明,利用行星球磨机制作艾斯卡试剂,选择试剂空白为参比液,在19℃的恒温环境下,采用36 g/L的碳酸钠溶液制作0~8μg/mL标准曲线,样品采用0~300、300~500、500~750℃三阶段升温,750℃保持30 min的烧结程序,乙酸用量为5 mL时可以得到可靠的结果。方法克服了艾斯卡试剂制作困难、样品烧结结块及实验反应速率过快等困难。通过方法学考察表明,碘元素校准曲线系数>0.999,方法检出限为0.2 mg/kg;测定GSS36、GSS37、GSS38、GSS40、GSS47、GSS48、GSS49等9种国家一级标准物质,结果均在参考值范围内,相对标准偏差RSD<5%。方法测定的结果准确度及精密度高、检出限低,能减少碘记忆效应的存在,适用于地球化学勘察土壤样品中碘的测定。
Iodine is one of the important elements to evaluate the environment,and it is a commonly measured element in geochemical survey samples.Through the discussion of the advantages and disadvantages of the production of the Eska reagent handmade and the planet ball mill,selection of reference solution,the effects of different environmental temperature conditions of 17-25℃on the experimental results,the standard curve was prepared by using the full procedure blank solution and 36 g/L sodium carbonate solution,and the linear range of the standard curve was obtained.At the same time,the effects of sample sintering time and temperature,and the amount of acetic acid on the test absorbance of the sample were also investigated.A method was established for the determination of iodine by catalytic spectrophotometry with the time sequence of the decomposition of Eska reagent and the extraction of samples with hot water.The results showed that using the planet ball grinding mechanism to make an Eska reagent,selecting reagents blank as the reference solution,under the constant temperature environment of 19℃,using 36 g/L sodium carbonate solution to produce 0-8μg/mL standard curve,the samples were heated at 0-300,300-500,500-750℃ in three stages,750℃ for 30 min sintering procedure,and the amount of acetic acid was 5 mL,reliable results could be obtained.This method overcomes the difficulties such as Eska reagent production,sample sintering block,and too fast experimental response rate.The methodological investigation shows that the calibration curve coefficient of iodine element is more than 0.999,and the detection limit is 0.2 mg/kg,nine national primary standard substances(GSS36,GSS37,GSS38,GSS40,GSS47,GSS48,GSS49,etc.)are determined,and the results are within the range of reference values,with RSD<5%.The method has high accuracy and precision,low detection limit,and reduces the existence of iodine memory effect.It is suitable for the determination of iodine in soil samples for geochemical investigation.
作者
颜巧丽
杨远
聂小力
钟奕昕
刘杰
黄浩浩
YAN Qiaoli;YANG Yuan;NIE Xiaoli;ZHONG Yixin;LIU Jie;HUANG Haohao(Changsha Natural Resources Comprehensive Survey,China Geological Survey,Changsha,Hunan 410600,China;College of Resources and Environment,Hunan Agricultural University,Changsha,Hunan 410128,China)
出处
《中国无机分析化学》
CAS
北大核心
2023年第6期582-589,共8页
Chinese Journal of Inorganic Analytical Chemistry
基金
中国地质调查局自然资源综合调查项目(DD20220855)。
关键词
催化分光光度法
时间程序
碘
地球化学
地质样品
土壤
catalytic photometric method
time program
iodine
earth chemistry
geological sample
soil
