碱溶液提取-电感耦合等离子体原子发射光谱法测定土壤中六价铬的含量  

Determination of Hexavalent Chromium in Soil by Inductively Coupled Plasma Atomic Emission Spectrometry with Alkali Solution Extraction

作　　者：门倩妮 李荣华 甘黎明 冯博鑫 MEN Qianni;LI Ronghua;GAN Liming;FENG Boxin(Xi'an Center of Mineral Resource Survey,China Geological Survey,Xi'an 7i0100,China)

机构地区：[1]中国地质调查局西安矿产资源调查中心,西安710100

出　　处：《理化检验（化学分册）》2024年第1期101-104,共4页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：熊耳山-伏牛山矿集区生态修复支撑调查项目(DD20208079)。

摘　　要：针对HJ 1082-2019存在的检测范围窄、高盐分带来的基线漂移以及谱线干扰等情况,提出了题示方法。取样品5.0 g,加入50 mL含0.5 mol·L^(-1)氢氧化钠和0.28 mol·L^(-1)碳酸钠的碱提取液(pH>11.5)、0.4 g氯化镁和0.5 mL磷酸盐缓冲液(pH 7.0),放入40 mm磁子,于95℃以速率600 r·min^(-1)搅拌60 min,冷却,以转速4000 r·min^(-1)离心5 min。分取滤液25 mL,调节酸度至pH 7.0~7.5,然后用水定容至50 mL。分取1 mL,用水稀释10倍后,采用电感耦合等离子原子发射光谱法测定其中六价铬的含量。结果表明:六价铬标准曲线的线性范围在2 mg·L^(-1)以内,检出限(3.143s)为0.096 mg·kg^(-1);5种土壤中六价铬成分分析标准物质的测定值均在认定值的不确定度范围内,且测定值的相对标准偏差(n=6)为1.1%~3.7%;按照标准加入法对实际样品进行加标回收试验,回收率为90.0%~112%。In view of the narrow detection range,baseline drift and spectral line interference caused by high salinity of HJ 1082-2019,a method mentioned by the title was proposed.The sample(5.0 g)was taken,and 50 mL of alkali extracting solution containing 0.5 mol·L^(-1)sodium hydroxide and 0.28 mol·L^(-1)sodium carbonate(pH>11.5),0.4 g of magnesium chloride and 0.5 mL of phosphate buffer sohution(pH 7.0)were added.A 40 mm magneton was added into the above mixture,and stir was conducted at 95℃for 60 min at rate of 600 r·min^(-1).After cooling,the mixed solution was centrifuged at speed of 4000 r·min^(-1)for 5 min.An aliquot(25 mL)of filtrate was taken,and its acidity was adjusted to pH 7.0-7.5,then the volume was made up to 50 mL with water.An aliquot(1 mL)was diluted 10 times with water,in which hexavalent chromium was determined by inductively coupled plasma atomic emission spectrometry.As shown by the results,the linear range of standard curve for hexavalent chromium was within 2 mg·L^(-1),and the detection limit(3.143s)was 0.096 mg·kg^(-1).The determined values of 5 standard substances for the analysis of hexavalent chromium in soil were within the uncertainty ranges of the identified values,and RSDs(n=6)of the determined values were in the range of 1.1%-3.7%.Test for recovery was made on the actual samples according to the standard addition method,giving results in the range of 90.0%-112%.

关 键 词：土壤 六价铬 碱溶液 电感耦合等离子体原子发射光谱法 搅拌 

分 类 号：O657.63[理学—分析化学]