發(fā)布時間：2019-06-25 21:03

【摘要】：根據(jù)國家文件的有關(guān)要求,將《水質(zhì)烷基汞的測定液相色譜/原子熒光法》列入2016年度環(huán)保部標(biāo)準(zhǔn)制修訂計劃,項目統(tǒng)一編號為2016-16。本文采用液相色譜-原子熒光法(LC-AFS)測定水中甲基汞和乙基汞,主要內(nèi)容和結(jié)論如下:首先,對LC-AFS儀器參數(shù)進(jìn)行優(yōu)化后的條件為:C18色譜柱分離,流動相為5%甲醇+1.2g/L L-半胱氨酸+4.62g/L乙酸銨,流速為1.0mL/min,氧化劑、載流、還原劑分別為0.2%K2S2O8+0.5%KOH、5%HCl、0.2%KBH4+0.5%KOH,燈電流:30mA、負(fù)高壓:300V,載氣流量:300ml/min、屏蔽氣流量:1000ml/min。以最佳條件測定標(biāo)準(zhǔn)曲線,甲基汞和乙基汞在(0.1~10)μg/L濃度范圍內(nèi)線性關(guān)系良好,相關(guān)系數(shù)優(yōu)于0.9990。第二,以液液萃取和固相萃取對水樣進(jìn)行預(yù)處理,通過LC-AFS測定后計算加標(biāo)回收率。對于低、中、高3種濃度,液液萃取對甲基汞、乙基汞的回收率在76%~114%之間,相對標(biāo)準(zhǔn)偏差為4.1%~7.4%;以自制巰基棉、C18萃取盤、C18萃取柱3種固相萃取法進(jìn)行實驗,對應(yīng)低、中、高3種濃度,巰基棉富集對甲基汞的回收率分別為103%、96.0%、65.8%,乙基汞的回收率分別為96.3%、54.6%、23.0%,回收率不穩(wěn)定;C18萃取盤對甲基汞、乙基汞的回收率在34.4%~57.4%之間;C18萃取柱對甲基汞、乙基汞的回收率分別在55.4%~73.1%之間。通過比較回收率、方法檢出限、操作難易、成本等因素,液液萃取為最優(yōu)方法。第三,以液液萃取-LC-AFS方法進(jìn)行實際水樣及加標(biāo)回收率的測定,實際水樣包括自來水、水庫及污水處理廠出口水樣。自來水及水庫水中均未檢測到甲基汞和乙基汞;僅在團(tuán)島污水處理廠、婁山河污水處理廠檢測到甲基汞濃度分別為0.29 ng/L、0.11 ng/L,低于《污水綜合排放標(biāo)準(zhǔn)》等標(biāo)準(zhǔn)中的限值。整體回收率在74.0%~116.7%之間,可滿足分析要求。本課題通過改進(jìn)現(xiàn)有方法的不足之處,建立了適用于水中甲基汞、乙基汞的分析方法,確�；|(zhì)干擾最少,降低樣品的檢出限,提高精密度、準(zhǔn)確性及重復(fù)性。以該方法測定實際水樣,以期為今后水中甲基汞和乙基汞含量的分析、污染防治工作及相關(guān)標(biāo)準(zhǔn)的修訂提供方法依據(jù)。
[Abstract]:According to the relevant requirements of the national document, the determination of alkyl mercury in water quality by liquid chromatography / atomic fluorescence spectrometry was included in the revised plan of the standard system of the Ministry of Environmental Protection in 2016. the unified number of the project is 2016 / 16. In this paper, methyl mercury and ethyl mercury in water were determined by liquid chromatography-atomic fluorescence spectrometry (LC-AFS). The main contents and conclusions are as follows: firstly, the parameters of LC-AFS instrument are optimized as follows: C _ (18) column separation, mobile phase 5% methanol 1.2g/L L-cystine 4.62g/L ammonium acetate, flow rate 1.0 mL / min, oxidant, current carrier and reductant 0.5% KOH, respectively. 5% HCL, 0.2% KBH4 0.5% KOH, lamp current: 30mA, negative high voltage: 300V, carrier gas flow rate: 300ml min, shielded gas flow rate: 1000ml min. The linear range of methylmercury and ethyl mercury was (0.1 渭 g 路L) 渭 g 路L ~ (- 1), and the correlation coefficient was better than 0.999 0 渭 g 路L ~ (- 1) in the range of (0.1 渭 g 路L) 渭 g 路L ~ (- 1). Secondly, the water samples were pretreated with liquid-liquid extraction and solid phase extraction, and the standard recovery was calculated after LC-AFS determination. For low, medium and high concentrations, the recovery of liquid-liquid extraction of methylmercury and ethyl mercury is between 76% and 11.4%, and the relative standard deviation is 4.1% 鈮，

本文編號：2506004