超声提取-抗坏血酸还原-催化光度法测定土壤中的碘  

Determination of iodine in soil by ultrasonic extraction-ascorbic acid reduction-catalytic spectrophotometry

作　　者：字雨姝 张皓 吴亮 黄宇琪 ZI Yushu;ZHANG Hao;WU Liang;HUANG Yuqi(Changsha Uranium Geology Research Institute,Hunan Engineering Technology Research Center for evaluation and comprehensive utilization of associated radioactive mineral resources,Changsha 410007,China)

机构地区：[1]核工业二三〇研究所,湖南省伴生放射性矿产资源评价与综合利用工程技术研究中心,长沙410007

出　　处：《化学分析计量》2023年第9期29-33,共5页Chemical Analysis And Meterage

摘　　要：建立超声提取-抗坏血酸还原-催化光度法测定土壤中碘含量的方法。将碳酸钠和氧化锌研磨后过孔径为0.25 mm筛,按质量比为3∶2混合均匀,制成艾斯卡试剂。将土壤样品与艾斯卡试剂半熔后用超声提取试样中的碘,分取上清液依次加入抗坏血酸和乙酸,使氧化态的碘和碘单质全部变为碘离子,最后加入4,4'-四甲基二氨基苯甲烷、氯胺T,用分光光度计测定。该方法碘元素的质量浓度在0.0025~0.08 mg/L范围内与吸光度具有良好的线性关系,相关系数为0.9995,检出限为0.25 mg/kg。采用所建方法对土壤样品进行6次平行测定,测定结果的相对标准偏差为3.50%~9.40%;对国家标准物质GBW 07409、GBW 07408a、GBW 07407a 3种标准物质进行测定,测定值均在标准值范围内,相对误差分别为3.41%、0.63%、1.05%。该方法适合于大批量土壤样品中碘的测定。An ultrasonic extraction-ascorbic acid reduction-catalytic photometric method for determining iodine content in soil was established.Esca reagent was prepared by grinding sodium carbonate and zinc oxide into 0.25 mm sieve with a mass ratio of 3∶2.The iodine in the sample was extracted by ultrasound after semi-melting with Escka reagent,and the supernatant was separated and added successively with ascorbic acid and acetic acid,so that the oxidized iodine and iodine element were all changed into iodide ions,to consistent with the valence state of iodine in the curve.Finally 4,4'-tetramethyldiaminobenzene methane and chloramine T was added,and the determination was performed by spectrophotometer.In this method,the mass concentration of iodine had a good linear relationship with the absorbance intensity in the range of 0.0025-0.08 mg/L,the correlation coefficient was 0.9995,and the detection limit was 0.25 mg/kg.The proposed method was used to determine the soil samples for 6 times in parallel,and the relative standard deviations of the results were 3.50%-9.40%The national reference materials GBW 07409,GBW 07408a and GBW 07407a were measured,and the measured values were within the standard values,and the relative errors were 3.41%,0.63%and 1.05%.The method is simple,and it is suitable for the determination of iodine in large quantities of soil samples.

关 键 词：超声提取 抗坏血酸还原 催化光度法 土壤 碘 

分 类 号：O657.3[理学—分析化学]