）的审议，形成正式的CAIA标准，已于2019年9月10日正式发布，并于2019年10月1日正式实施。 Recently, the Standardization Committee of China Analytical and Testing Association passed the review of “Inductively Coupled Plasma Mass Spectrometry for the Determination of Cadmium in Marine Aquaculture” ( T / CAIA / SH012-2019 ), forming a formal CAIA standard. It was officially released and officially implemented on October 1 , 2019 .
），具有灵敏度高、检出限低、线性范围宽、干扰少等优点，适用于海水中μg/L或更低含量镉的测定。 Inductively coupled plasma mass spectrometry ( ICP-MS ) has the advantages of high sensitivity, low detection limit, wide linear range, and low interference. It is suitable for the determination of μg / L or lower cadmium in seawater.
电感耦合等离子体质谱仪（ ICP-MS 2000B ） Figure 1. Inductively coupled plasma mass spectrometer ( ICP-MS 2000B )
原理 1. principle
， counts per second ），利用响应强度与离子浓度成正比关系，对溶液中待测元素进行定量分析。 The sample is diluted with dilute acid, atomized by a nebulizer, and sent to a high-temperature plasma for drying, atomization, and ionization. The ions generated by the ionization enter the mass spectrometer through the interface chamber, and then pass through the ion lens system and mass analyzer to the detector. The detector responds to the corresponding measured element ions (ion counts per second cps , counts per second ), and uses the response intensity to be proportional to the ion concentration to quantitatively analyze the measured elements in the solution.
仪器试剂 2. Instrument reagent
，江苏天瑞仪器股份有限公司） Inductively coupled plasma mass spectrometer ( ICP-MS2000B , Jiangsu Tianrui Instrument Co., Ltd.)
，萨劳） Nitric acid ( AR , Sarawo)
， inorganic ventures ） Element standard solution ( 10 mg / L , inorganic ventures )
，密理博） Ultrapure water (resistivity up to 18.25MΩ • cm , Millipore)
前处理 3. Pre-treatment
海水国家标准物质（ GBW(E)080040 ），以（ 1+24 ）硝酸溶液定容至10.0mL 。 Accurately transfer 1.0mL national standard material of seawater ( GBW (E) 080040 ), and make up to 10.0mL with ( 1 + 24 ) nitric acid solution. ，以离线方式加入，最终定容浓度为10 μg/L 。 The internal standard element In was added offline, and the final constant volume concentration was 10 μg / L. Make parallel samples and two samples blank at the same time.
测试数据 4. Test data
，见表1 ）。 Under the optimized working conditions of the instrument, the blank and parallel samples of the prepared sample were measured, and one parallel sample was measured five times in parallel, and the relative standard deviation of the results of the five times was calculated ( RSD /% , see Table 1 ).
海水标准物质测试结果 Table 1. Test results of seawater reference materials
Standard value / μg / L
Measured value / μg / L
Cd 114 Cd
± 0.06 1.00 ± 0.06
测定海水标准物质中Cd的相对标准偏差（ RSD ）为7.3% ，测试结果平均值为1.05μg/L ，在标准值（ 1.00 ± 0.06μg/L ）范围内。 As can be seen from the above table, the relative standard deviation ( RSD ) of Cd in seawater reference materials measured by ICP-MS 2000B is 7.3% , and the average test result is 1.05 μg / L , which is within the standard value ( 1.00 ± 0.06 μg / L ).
T/CAIA/SH012-2019 ，海水养殖水镉的测定电感耦合等离子体质谱法，中国分析测试协会， 2019 。 1. T / CAIA / SH012-2019 , Determination of Cadmium in Marine Aquaculture, Inductively Coupled Plasma Mass Spectrometry, China Analytical Testing Association, 2019 .