二维离子排斥-离子交换色谱配合阀切换技术测定G2级磷酸中的痕量阴离子  

Determination of trace anions in G2-grade phosphoric acid using two-dimensional ion-exclusion-ion-exchange chromatography with valve-switching technology

作　　者：王佳鼎 唐高[1] 鹿燕 卢珩俊 叶涛 WANG Jiading;TANG Gao;LU Yan;LU Hengjun;YE Tao(College of Materials and Chemistry,China Jiliang University,Hangzhou 310018,China;Zhejiang Fangyuan Test Croup Co.,Ltd.,Hangzhou 310018,China)

机构地区：[1]中国计量大学材料与化学学院,浙江杭州310018 [2]浙江方圆检测集团股份有限公司,浙江杭州310018

出　　处：《色谱》2025年第3期237-244,共8页Chinese Journal of Chromatography

基　　金：浙江省市场监管局“雏鹰计划”培育项目(CY2022005);浙江省教育厅科研资助项目(Y202353765).

摘　　要：本研究建立了在超净环境下基于二维离子排斥-离子交换色谱配合阀切换技术测定G2级磷酸中痕量阴离子含量的方法。通过比较确定了第一维超纯水流经离子排斥柱的最佳柱流速为0.5 mL/min,并确定阀切换窗口,以尽可能降低PO 43-在阴离子富集柱上的富集水平,减小了磷酸基体的干扰;采用抑制器外接水模式,降低了基线噪声;优化了第二维的淋洗程序,实现了痕量目标阴离子的良好分离,避免了硝酸根的假阳性风险。结果表明:Cl^(-)、Br^(-)、NO_(3)^(-)和SO_(4)^(2-)4种阴离子在0.5~20μg/kg含量范围内呈现良好的线性关系,相关系数>0.999;检出限和定量限分别为0.09~0.29μg/kg和0.29~0.97μg/kg。在4个添加水平下,各阴离子的加标回收率为91.7%~103.6%,RSD为0.1%~4.9%。本方法具有重复进样稳定性好、检出限低的优势,方法的精密度和准确度高,能满足G2级磷酸中痕量阴离子的检测需求。此外,通过单一标准物质保留时间定性,本研究在G2级磷酸中发现除常规阴离子外,可能还存在以亚磷酸根(HPO 3-)和六偏磷酸根(PO 3-)6为代表的其他磷系阴离子和阴离子簇。这一发现对于今后更高纯度磷酸的纯化工艺开发具有一定的理论和应用意义。This study established a method for determining trace anions in G2-grade phosphoric acid under ultra-clean conditions that used two-dimensional ion-exclusion-ion-exchange chromatography coupled with valve-switching technology.The optimal flow rate of ultrapure water through the ion-exclusion column in the first dimension was determined to be 0.5 mL/min through comparative experiments.The valve-switching window was optimized to minimize enriching PO 43-on the anion-enrichment column and reduce interference from the phosphoric-acid matrix.The use of external water mode for the suppressor led to lower baseline noise,and optimizing the elution program of the second dimension enabled target trace anions to be well separated,thereby avoiding the risk of a false positive for NO 3-.The anions of Cl^(-),Br^(-),NO_(3)^(-),and SO_(4)^(2-)exhibited good linearities within the 0.5-20μg/kg,with correlation coefficients≥0.999.The limits of detection(LODs)and quantification(LOQs)were 0.09-0.29μg/kg and 0.29-0.97μg/kg,respectively.The spiked recoveries of each anion at four spiked levels ranged from 91.7%to 103.6%,with RSDs of 0.1%-4.9%.The developed method demonstrated excellent stability through repeated injections,and low detection limits;it is highly precise and accurate,and meets the detection requirements for trace anions in G2-grade phosphoric acid.Additionally,retention-time comparisons with single standard substances led to the discovery of other phosphorus-related anions and anion clusters,such as hypophosphite(HPO 3-)and hexametaphosphate(PO 3-)6,in G2-grade phosphoric acid,in addition to conventional anions.This finding is theoretically and practically significant for the future development of purification processes for higher-purity phosphoric acid.

关 键 词：电子级磷酸 痕量阴离子 阀切换 二维离子色谱 

分 类 号：O658[理学—分析化学]