水质分析质量控制用29种VOCs混合标准样品的研制及其应用

发布时间：2018-04-23 20:17

  本文选题：挥发性有机物 + 标准样品　； 参考：《北京化工大学》2016年硕士论文

【摘要】：挥发性有机物(Volatile Organic Compounds, VOCs)作为重要的水质评价指标之一,在多项环境标准中明确规定了限值。但是,水体中VOCs的含量少且种类多,因而如何保证水中VOCs测试数据的准确及可靠成为水质分析质量控制的难点。标准样品是环境监测质量控制手段之一,近年来环境保护的压力和分析方法的更新对水体VOCs标准样品的需求不断提高。目前市售的VOCs标准样品多来自国外,其种类和浓度范围不能满足我国实际监测的需求。为此,本文研制了一种涵盖我国环境水标准中涉及的29种VOCs混合标准样品溶液,解决了研制过程中的关键技术问题,并对标样的均匀性和稳定性进行了评价。主要研究内容如下：1、首先采用气密注射预先配制氯乙烯甲醇溶液,然后标准称量其余组分并混匀,按照标准样品工作导则将配制好的溶液进行灌封、分装。对制备好的VOCs混合标样进行均匀性检验,F检验统计结果表明均匀性合格。2、对所制备的VOCs甲醇标样进行稳定性研究。长期稳定性检验结果表明标准样品可以在-18℃的条件稳定保存18个月；然而由于在室温及4℃保存条件下,环氧氯丙烷易分解影响量值的准确,因此进一步对其进行了短期稳定性检验,结果表明环氧氯丙烷的浓度受温度影响较大,建议该VOCs混合标样在运输过程中控制低温环境；转移至实验室时,可短期保存于4℃或室温环境,并尽快完成测量以保证结果的准确性。3、建立了吹扫捕集-气质联用法检测水体中VOCs的检测条件：吹扫(时间11 min,流速40 mL/min)-干吹扫时间1 min-预脱附(温度180℃)-吹扫(温度30℃,时间11 min)-解吸附(温度190℃,时间2 min)-烘烤(时间8 min,温度230℃)。将研制的29种VOCs混合标样采用此方法进行定值分析,并将数据结果与6家实验室进行统计,依次进行Dixon检验、Grubbs检验、Cochran检验,剔除离群值,计算出标准样品的标准值,并整合配制过程、均匀性检验、稳定性研究、定值过程各步的不确定度分量,计算标准样品的扩展不确定度。4、将建立的检测方法应用于环境不同水体中VOCs检测,用研制的质控用29种VOCs标准样品进行加标回收试验,方法线性良好,加标回收率在60%～130%之间,检测限达到0.04～2.82μg·L-1,精密度在0.7%-7.5%之间。本论文研制的水质分析质量控制用29种VOCs标准样品符合实际水体中VOCs的监测需求,完善了我国VOCs昆合标准样品体系,为监测实际水体中的VOCs提供了一种质量控制手段。
[Abstract]:Volatile Organic components (VOCs), as one of the important water quality evaluation indexes, has specified the limit value in many environmental standards. However, the content of VOCs in water is small and there are many kinds, so how to ensure the accuracy and reliability of VOCs test data in water becomes the difficulty of quality control of water quality analysis. Standard samples are one of the quality control methods for environmental monitoring. In recent years, the pressure of environmental protection and the updating of analytical methods have increased the demand for VOCs standard samples of water body. At present, most of the VOCs standard samples on the market come from abroad, and their types and concentration range can not meet the needs of China's actual monitoring. In this paper, a mixture of 29 kinds of VOCs sample solution which covers the environmental water standard in China is developed. The key technical problems in the process are solved, and the uniformity and stability of the standard sample are evaluated. The main research contents are as follows: firstly, the solution of vinyl chloride was pre-prepared by air-tight injection, then the remaining components of the standard weighing were mixed and mixed, and the prepared solution was sealed and divided according to the work guidelines of the standard sample. The uniformity test of the prepared VOCs mixed standard samples was carried out. The F test results showed that the uniformity was qualified. The stability of the prepared VOCs methanol standard samples was studied. The results of long-term stability test showed that the standard samples could be stably preserved at -18 鈩，

本文编号：1793481