一个简便快速测定CO的纳米金表面等离子体共振吸收光谱法

CO主要由火焰或烤炉等碳的不完全燃烧所产生，是一种常温下为无色、无臭的有毒气体，人们受一氧化碳的污染在慢性中毒时完全意识不到它，有时甚至有舒适的感觉，这些特性更增加了它的危害性。因此，探索简便快速灵敏的CO检测方法具有重要意义。研究表明，在pH 7.2 磷酸盐缓冲溶液中，一氧化碳还原HAuCl₄ 生成近似球形的金纳米粒子(NG)，其平均粒径为45 nm，在1.70, 2.20和9.70 keV处产生3个金元素的能谱峰，在540 nm处产生一个表面等离子体共振(SPR) 吸收峰。采用分光光度法优化了分析条件，选择磷酸盐缓冲缓冲溶液的pH为7.2，磷酸盐缓冲浓度为40 mmoL·L-1，HAuCl₄浓度为40.0 μg·mL-1，反应时间为5 min。在选定条件下，CO浓度在0.2～8.75 μg·mL-1范围内与其SPR吸收峰峰值成线性关系，检出限为0.1 μg·mL-1 CO。考察了共存物质对测定1.0 μg·mL-1 CO的影响。结果表明, 当相对误差在±5%之内，200倍的SO2-₃, PO3-₄, SO2-₄、CO2-₃, NO-₃;100倍的Zn2+, K+, BrO-₃, Na₂S, 乙醇, 甲醇;80倍的Ni2+，Cr3+，Co2+，Ca2+, Mg2+, Fe3+, 葡萄糖, Pb2+, Al3+, SeO2-₃, Na₂S₂O₃，甲醛;50倍的Mn2+不干扰测定。这表明该SPR光度法具有较好的选择性。采用本法测定了空气样品中CO含量，结果与气相色谱法一致，相对误差在1.8%～4.2%之间。

A Facile Nanogold Surface Plasmon Resonance Absorption Method for CO Tracing

The detection of gas pollutants in atmosphere and indoor air is very important to human health and safety.Monoxide carbon (CO)is a common gas pollutant with high toxicity that mainly comes from the inadequacy oxidization of carbon such as oil,coal and petrol inadequacy combustion,auto-gas and some natural disasters whose limit value in air is lower than 6.0 mg· m-3 in the national standard.Due to its toxicity and uneasy detection,it is one of very dangerous component in the silent killer. Recently,several methods,including infra-red absorption,gas chromatography,potentiometry,Hg replacement,spectropho-tometry,I2 O5 and PdCl2 nake-eye,semiconductor sensor have been reportedly used for the detection of CO.To our best knowl-edge,there are no SPR absorption methods for CO,based on the NG SPR absorption.In this paper,the reaction between CO and HAuCl4 was studied with absorption spectrophotometry and transmission electron microscopy (TEM)while a simple and rapid SPR absorption method was developed for the determination of trace CO.In pH 7.2 phosphate buffer solutions,monoxide carbon reduced HAuCl4 to form nanogold (NG)particles with the size of about 45 nm that exhibited surface plasmon resonance (SPR)absorption peak at 540 nm and three energy spectral peaks at 1.70 keV,2.20 and 9.70 keV for gold element.The ana-lytical conditions were examined,and a pH 7.2 phosphate buffer solution with a concentration of 40 mmoL·L-1 PO3 -4 ,a con-centration of 40.0 μg· mL-1 HAuCl4 and a reaction time of 5 min was selected for use.Under the selected conditions,the SPR absorption peak value was linear to CO concentration in the range of 0.2~8.75 μg· mL-1 ,with a detection limit of 0.1 μg· mL-1 CO.According to the procedure,the influence of coexistent substances on the determination of 1.0 mg·L-1 CO was test-ed,with a relative error of ±5%.Results indicated that 200 times SO2-3 ,PO3 -4 ,SO2-4 ,CO2-3 and NO-3 ,100 times Zn2+ ,K+ , BrO-3 ,Na2 S,ethanol,methanol,80 times Ni2+ ,Cr3 + ,Co2+ ,Ca2+ ,Mg2+ ,Fe3 + ,glucose,Pb2+ ,Al3 + ,SeO2-3 ,Na2 S2 O3 , formaldehyde,50 times Mn2+ do not interfere with the determination.It showed that this SPR method had good selectivity.The CO content in air samples was determined with the SPR method,with a relative standard deviation (RSD)of 1.8%~4.2%,the SPR method results were agreement with that of the gas chromatography (GC).