Title: [Establishment of arsenic speciation analysis method and application in rice].
Abstract: Objective: A new ion exchange column technology was used to establish an efficient and sensitive method for the detection of inorganic arsenic. Methods: Based on the new As Specia Fast Column, the pretreatment methods, liquid phase separation and mass spectrometry determination conditions of inorganic arsenic in rice were optimized. Finally, arsenic compounds were separated by As Specia Fast Column and detected by liquid chromatography inductively coupled plasma mass spectrometry. The external standard method was used for quantitative analysis. The detection limit, precision and accuracy of the method were determined by measuring the content of arsenic compounds in rice samples and rice standard samples. At the same time, three Guangdong rice samples were selected as the experimental samples of this study, and 1 g of each sample was weighed and measured in parallel three times. The method was compared with the method of liquid chromatography-atomic fluorescence spectrometry (LC-AFS) and liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS) in the national standard. Results: The inorganic arsenic in rice was extracted with 0.5% nitric acid solution at 65 ℃ for 15 h, and the pH was adjusted to alkaline. The mobile phase A (8 mmol/L HNO(3), 50 mmol/L NH(3)·H(2)O) and mobile phase B (40 mmol/L HNO(3), 80 mmol/L NH(3)·H(2)O) were used as the mobile phase gradient elution (93%) . Five arsenic compounds can reach baseline separation under the conditions of RF power of 1 500 W and atomization gas flow of 0.97 L/min. The detection limits ranged from 0.114 to 0.331 μg/L, and the inorganic arsenic content in rice samples ranged from 0.063 to 0.232 mg/kg. The results of determination of arsenic compounds in rice flour reference materials were all within the uncertainty range indicated by the standard. The recoveries were 86.7%~106.7%, and the precision was 1.9%-12.5%. Compared with national standards, the results of determination of arsenate in rice were relatively close (using this method, LC-AFS, LC-ICP-MS to detect the content of arsenate in rice samples 1 was 0.231, 0.226, 0.236 mg/kg, respectively). However, due to insufficient sensitivity, the national standard method is difficult to detect low levels of arsenic compounds (Arsenobetaine was not detected in rice sample 1). The method can detect the content of arsenobetaine in rice sample 1 was 0.023 mg/kg. Conclusion: The established method can meet the requirements of inorganic arsenic determination in rice, and it is more rapid and accurate than the current national standard. It can better monitor and evaluate the content of i-As in rice, and provide accurate data for comprehensively grasping and evaluating the safety of rice consumption of residents.目的: 采用新型离子交换柱技术建立高效、灵敏的无机砷的检测方法,并检测大米基质中的砷含量。 方法: 基于新型离子交换柱,对大米中无机砷分析的前处理方法、液相分离及质谱测定条件进行优化,最终砷形态化合物以新型离子交换柱分离,液相色谱-电感耦合等离子体质谱联用法进行检测。采用外标法定量,通过检测大米样品和大米标准样品中砷形态化合物含量,对方法的检出限、精密度和准确度进行评价。同时选取3种广东市售大米作为本研究的实验样品,每份称取试样1 g,平行测量3次,将本方法与国家标准中的液相色谱-原子荧光光谱法(LC-AFS)、液相色谱-电感耦合等离子体质谱法(LC-ICP-MS)进行比较。 结果: 经检测,在以0.5%硝酸溶液在65 ℃超声水浴条件下,对大米中无机砷萃取1.5 h,调节pH至碱性时,大米的平均提取效率最高(>93%)。以流动相A(8 mmol/L HNO(3),50 mmol/L NH(3)·H(2)O)和流动相B(40 mmol/L HNO(3),80 mmol/L NH(3)·H(2)O)为流动相梯度洗脱,在射频功率1 500 W,雾化气流量0.97 L/min的测定条件下,5种砷形态化合物能达到基线分离,检出限范围在0.114~0.331 μg/L,大米样品中无机砷含量为0.063~0.232 mg/kg,测定大米粉标准物质中砷形态化合物结果均在其标示的不确定范围内,加标回收率为86.7%~106.7%,测定精密度分别为1.9%~12.5%。与国家标准相比,大米中砷酸盐中的测定结果较为接近,采用本研究、LC-AFS、LC-ICP-MS检测大米样品1砷酸盐的含量分别为0.231、0.226、0.236 mg/kg,而国标方法由于灵敏度不足,难以检出低含量砷形态化合物(大米样品1中均未检出砷甜菜碱)。方法可检出大米样品1中的砷甜菜碱含量为0.023 mg/kg。 结论: 本研究建立的方法能满足大米中无机砷的测量需求,相比现行国标,能较大程度地缩短了检测时间和提高效率,同时也降低了方法检出限,提高了方法灵敏度。.
Publication Year: 2018
Publication Date: 2018-10-06
Language: en
Type: article
Indexed In: ['pubmed']
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