He mass spectrometry for very low-level measurement of organic tritium in environmental samples

The design, setup and performance of a mass spectrometric system for the analysis of low to very low-level tritium in environmental samples are described. The tritium concentration is measured indirectly by the ³He ingrowth from radioactive decay after complete initial degassing of the sample. The analytical system is fully computer-controlled and consists in a commercial helium isotope mass spectrometer coupled with a high vacuum inlet system. A detection limit of 0.15 Bq/kg is routinely obtainable for sample sizes of 20 g of water equivalent and an accumulation time of three months. Larger samples (and/or longer accumulation time) can be used to obtain lower detection limits. In addition to the benefit of a lower detection limit, another advantage of this non-destructive method lies in the simplicity of the analytical procedure which strongly limits the risk of contamination. An inter-comparison was successfully performed with the conventional beta counting technique on lyophilized grass samples, in a range of tritium concentrations of environmental interest. It shows that the ³He mass spectrometry method yields results that are fully consistent with the conventional liquid scintillation technique over a wide range of tritium concentrations.     

气相色谱/质谱联用法测定饮用水源水中苯胺类化合物

采用液液萃取-气相色谱/质谱联用法测定饮用水源水中19种苯胺类化合物,选择DB-5MS色谱柱,讨论了pH值对回收率的影响.方法在0.500 mg/L～5.00 mg/L范围内线性良好,19种苯胺类化合物的检出限为0.016μg/L～0.067 μg/L,标准溶液平行测定的RSD为1.2％ -13.2％,实际样品加标回收...     

QuEChERS-超高效液相色谱-串联质谱法测定鱼血清中的精神活性物质

本文建立了一种同时测定鱼血清中19种精神活性物质的分析方法.该方法基于QuEChERS方法对样品进行提取和净化,待测物采用超高效液相色谱-串联质谱法(UPLC-MS/MS)进行分析,检测的19种精神活性物质均采用同位素内标法定量.该方法的方法检测限(MDL)范围为0.02-0.06 ng.mE-1,基质效应处于76.7...     

傅立叶变换红外光谱法在环境监测中的应用进展

综述了傅立叶变换红外光谱法在水环境监测、大气环境监测、固体和土壤环境监测,以及突发性环境污染事故、“防化学战争”和“反恐怖活动”应急监测中的应用,指出该方法已成为鉴别未知污染物和环境监测的重要工具。     

原子吸收光谱法测定污水中铅的最佳操作条件研究

主要研究了测定波长、工作电流、燃烧器高度、光谱通带、燃气与助燃气流量等操作条件对测定工业污水中铅含量的影响 ,确定了最佳的测试条件。     

生物大分子(DNA及蛋白质)加和物的质谱分析鉴别

本文论述了质谱在生物大分子（ＤＮＡ及蛋白质）加合物研究中的应用。讨论了烷基加合物、ＰＡＨ加合物、胺类加合物、蛋白加合物等方面的应用结果及特点,同时评述了质谱法的新进展电喷雾电离质谱技术（ＥＳＩＭＳ）在鉴别蛋白质加合物方面的某些成功例子,结果表明ＥＳＩＭＳ在生物大分子加合物的研究方面将会带来更多的新结果。     

离子色谱－原子吸收联用测定水体中的Fe(Ⅲ)和Fe(Ⅱ)

研究离子色谱（ＩＣ）与石墨炉原子吸收光谱联用测定水体中铁形态的方法,用Ｓｈｉｍ－ｐａｃｋ阳离子交换柱分离Ｆｅ（Ⅲ）和Ｆｅ（Ⅱ）,用石墨炉原子吸收法检测,Ｆｅ（Ⅱ）和Ｆｅ（Ⅲ）的检出限分别为３．８ｎｇ／ｍｌ和７．７ｎｇ／ｍｌ,本方法已用于检测自来水和河水的铁的价态,取得了令人满意的结果。     

ASsessment Of Alcohol Ethoxylate Surfactants And Fatty Alcohols Mixtures In River Sediments And Prospective Risk Assessment

A feasible and relatively readily available analytical method was adapted for the assessment of alcohol ethoxylates (AE) and fatty alcohols (FA) in sediments. This study illustrates the simultaneous measurement of 38 of 114 possible alcohol ethoxylate ethoxymers (AE) and fatty alcohols (FA) found in commercially important AE products. We predicted toxicity for all identified fractions, as well as the total mixture toxicity, relative to three exposure scenarios via sewage treatment plants (STP) for these widely used chemicals in consumer products and hence generate a preliminary environmental risk screening for AE and FA in sediments. The method is based on derivatization of solvent or solid-phase extracts with 2-fluoro-N-methylpyridinium p-toluenesulfonate (Pyr+). The derivatized extracts were analyzed with liquid chromatography/mass spectrometry (LC/MS) operating in the positive ion electrospray mode. The extraction efficiency of AE and FA in three different sediments of varying composition was evaluated with spike-recovery studies, ranging from 64% to 80%. The detection limits for individual ethoxymers typically ranged from 1 to 5ngg⁻¹on a dry weight basis. The mean limit of detection (LOD) was 6ngg⁻¹and the median LOD was 3ngg⁻¹. AE and FA in sediments were found to be stable for two weeks if preserved with 3% (v/v) formalin and stored at 4–6^∘C. Based on equilibrium partitioning, background concentrations of AE and FA were predicted to be below concentrations known to elicit chronically toxic effects. Total worst case mixture toxicities for all AE ethoxymers combined with FA were predicted to result in a risk quotient less than 0.6. Activated sludge treatment (STP) significantly reduced the release of total AE and FA by four-fold, suggesting that the total mixture risk quotient would be < 0.15 for sediment dependent organisms.     

Characterization of the Leachate in an Urban Landfill by Physicochemical Analysis and Solid Phase Microextraction-GC/MS

The aim of this study is to evaluate extensively the characterization and identification of major pollutant parameters by paying attention to the organic chemical pollution for unregulated dumping site leachate in Eskişehir/Turkey. The study that is first and only one research has been very important data related with before new sanitary landfill site in Eskişehir city. For this purpose, in this study leachate samples were collected in-situ at monthly interval for a period of 8 months. Firstly, thirty three physicochemical parameters were monitored. Secondly, SPME technique was used for identification of organic pollutants. Meteorological data were also recorded for the same sampling period to correlate meteorological data and physicochemical parameters. Mean values are used in the correlation analysis. Correlation is shown only for the relationship between air temperature and NO₃ ⁻. No correlation has been found between rain and leachate quality parameters since the amount of rain was very low during the sampling period. However, analysis results were generally decreased in winter season when each parameter and each sampling point are examined separately. According to correlation between every parameter, especially solid content and dissolved oxygen concentration of leachate is affecting to other parameters. Also, sodium and potassium are changing proportionally with same parameters (suspended solids, fixed solids, dissolved oxygen) and high correlation between chloride and heavy metal concentration is showing. The results were statistically evaluated by use of SPSS 10.0 program. Second part of the study, the leachate was extracted by Solid Phase Microextraction (SPME) technique and then analyzed. Of the methodologies tested in this study, the best one selected was based on 100 μ m polydimethylsiloxane coated fiber (PDMS), headspace with heating (Δ HS) sampling mode and an extraction time of 15 min. at a temperature of 50 ^o C. Thirty three organic compounds in leachate were identified by GC/MS.     

高效液相色谱串联质谱法分析土壤中多溴联苯醚类化合物

建立了一种超高效液相色谱串联质谱法(UPLC-MS/MS)同时测定土壤中8种多溴联苯醚化合物(PBDEs)的方法,采用快速溶剂萃取(ASE)和凝胶净化色谱(GPC),经BEH反相C₁₈色谱柱分离,10 min内完成分离,使用含0.1%氨水的甲醇和水进行梯度洗脱,采用液相色谱-负离子-大气压化学电离(APCI)串联质谱,多反应监测模式(MRM),加入 ¹³C₁₂-BDE-139和¹³C₁₂-BDE-209内标作定量分析。结果表明:在优化的分析条件下,PBDEs的线性相关系数为0.998 8～0.999 5,方法检出限为0.22～0.59 μg/kg,在2个添加水平下,平均回收率为71%～126%,标准偏差为3%～18%,土壤实际质控样测定结果均在允许范围内。适合于土壤中PBDEs的快速分析,特别对于高溴代PBDEs,相比气相色谱质谱方法具有更快的分析速度和更好的稳定性。