实验技术与管理2025，Vol.42Issue(8)：22-28,7.DOI:10.16791/j.cnki.sjg.2025.08.004
小型化冷原子荧光检测器研制与应用
Development and application of miniaturized cold atomic fluorescence detector
摘要
Abstract
[Objective]Gas chromatography(GC)coupled with atomic fluorescence spectrometry(AFS)has been widely recognized for its high stability and accuracy in mercury detection.However,the large size,long tubing,and low utilization efficiency of conventional GC-AFS systems have limited their application in the analytical industry.Therefore,this study introduces a novel approach of shrinking a laboratory atomic fluorescence spectrometer to develop a miniaturized cold atomic fluorescence detector(AFD).[Methods]Instrument design and development:Through an integrated design,the AFD size was condensed to 1/30 that of a traditional atomic fluorescence spectrometer so that it can be directly mounted on a laboratory gas chromatograph as a platform.The AFD mainly consists of three modules:a high-temperature pyrolysis module,a fluorescence cell optical path module,and a tail gas collection module.With its temperature resistance limit above 1 000℃,the high-temperature pyrolysis module ensures the stable pyrolysis of alkylmercury samples at 900℃ while maintaining its own surface temperature below 60℃.Critical advancements through innovative designs of a composite housing with a gradient thermal insulation system and a hydrogen-oxygen combustion heating system were achieved in this module to meet the aforementioned technical requirements.The fluorescence cell optical path module features a compact fluorescence excitation optical path structure fabricated via 3D printing to ensure the accuracy of the specialized light-blocking system.Crucial technical innovations were implemented in its miniaturized optical,closed-loop light source control,and fluorescence cell excitation systems.The tail gas collection module primarily collects and manages the exhaust gas generated during detection,forming a closed-loop gas circulation system that effectively prevents gas diffusion(leakage rate＜0.1 μL/min)from the sample after detection.Simultaneously,this module integrates a gold wire trap specifically designed for mercury vapor(collection efficiency ≥ 99.8％)and facilitates the convergence of the sample gas flow during analysis,ensuring the stability of mercury vapor excitation.[Results]Performance testing and validation:The GC system equipped with the AFD achieved instrument detection limits of 0.073 7 and 0.094 4 pg(3σ,n=7)for methylmercury and ethylmercury,respectively.The system exhibited good linear response within the concentration range of 5～100 pg.The correlation coefficients(R2)of the calibration curves for methylmercury and ethylmercury were 0.9993 and 0.9999,respectively.The system also demonstrated good repeatability through six consecutive measurements of a 10-pg spiked sample.The relative standard deviations(RSDs)of the retention times for methylmercury and ethylmercury were 0.08％and 0.04％,respectively.Quantitative repeatability tests showed peak area RSDs of 1.63％and 1.86％for methylmercury and ethylmercury,respectively.Spike recovery experiments using the standard addition method revealed the recoveries for methylmercury and ethylmercury ranging from 78.2％to 102.2％and from 71.9％to 106.4％,respectively,across three spiking levels(5,20,and 100 pg).[Conclusions]A miniaturized cold AFD was successfully developed.By optimizing optical,gas path,and circuit integration,the AFD size was condensed to 1/30 that of a traditional cold atomic fluorescence spectrometer so that it can be directly mounted on a laboratory GC.This detector employs a synergistic design comprising a high-temperature pyrolysis module,fluorescence cell optical path module,and tail gas collection module,all of which ensure its high sensitivity and stability despite its small size.The developed system fills the gap in the laboratory GC market for alkyl mercury detection.Experimental results demonstrate its instrument detection limits of 0.073 7 and 0.094 4 pg for methylmercury and ethylmercury,respectively.关键词
气相色谱-原子荧光联用/小型化冷原子荧光检测器/甲基汞/乙基汞/痕量分析Key words
gas chromatography-atomic fluorescence spectrometry(GC-AFS)/miniaturized cold atomic fluorescence detector/methylmercury/ethylmercury/trace analysis分类
机械制造引用本文复制引用
陈璐,张丽娜,刘宇翔,周加才..小型化冷原子荧光检测器研制与应用[J].实验技术与管理,2025,42(8):22-28,7.基金项目
国家重点研发计划(2023YFF0722500) （2023YFF0722500）
