饮用水中硫化物的表面增强拉曼光谱检测方法

Rapid screening of sulfides in drinking water with surface-enhanced Raman spectroscopy

基于表面增强拉曼光谱(SERS)技术,建立了一种对饮用水中硫化物快速筛查的方法。以自制纳米/胶体金为表面增强基底,并利用紫外可见吸收光谱法和透射电镜(TEM)对该基底进行表征。待检样本经简单前处理,其中所含性质活泼的硫化物能与N,N二乙基对苯二胺(DPD)反应生成亚甲基蓝类化合物,该化合物经衍生后,在低功率(100 mW)和短积分时间(500 ms)条件下直接测试其拉曼光谱,并通过与硫化物衍生物的标准拉曼图谱比对进行定性分析。硫化物衍生物的SERS化学信号大约在453 cm-1和458 cm-1两处,分别对应于亚甲基蓝化合物中C—N—C的不同振动模式。本方法能够准确筛查饮用水中硫化物,整个测试过程少于10 min,检测限为0.02 mg/L,能够满足国家标准的限量要求。该方法简单、快速,结果准确,可以作为一种高灵敏的快速筛查手段。

We establish a method to rapid screen sulfide in drinking water based on surface enhanced Raman spectroscopy(SERS).Self-made colloidal gold was used as the surface enhanced substrate,that was characterized by UV-Vis absorption spectroscopy and transmission electron microscopy(TEM).After a simple pretreatment,the active sulfide contained in the sample could react with N,N-diethyl-p-phenylenediamine(DPD)to form methylene blue compounds.After derivatization,the Raman spectra of the methylene blue compounds were directly tested under the conditions of low power(100 mW)and short integration time(500 ms).Qualitative analysis was carried out by comparing the spectra of sulfide derivatives with the standard Raman spectra of sulfide derivatives.The SERS chemical signals of sulfide derivatives are observed at about 453 cm-1 and 458 cm-1,corresponding to different vibrational modes of C—N—C in methylene blue compounds.This method can accurately screen sulfide in drinking water.The time needed is than 10 minutes and the detection limit is 0.02 mg/L,to meet the limit requirements of national standards.This method is simple,rapid and accurate,can be used as a highly sensitive and rapid screening method.