香港海域翡翠贻贝(Perna viridis L.)中多氯联苯的研究

用气相色谱 毛细管双柱 电子捕获检测器研究了香港海域翡翠贻贝中多氯联苯(PCBs)的含量及其分布特征 ,结果表明 ,翡翠贻贝体内PCBs的污染现状与香港周边污染状况相符 ,在香港某些海域中翡翠贻贝体内PCBs有较高的含量 ,特别是靠近香港陆地的海域 ,PCBs总浓度最高达 3 0 3ng·g- 1 (干样 ) .PCBs同系物的分布亦有明显的不同特征 .运用二恶英毒性当量 (TEQ)表征翡翠贻贝中PCBs的毒性 ,TEQ最高值达 4 96ng·kg- 1 ,低于美国FDA允许值     

Evaluation of pesticides residues distribution in fresh and smoked body parts of Clarias gariepinus and assessment of possible health risks in Nigeria

Pesticides residues in fresh and smoked body parts of Clarias gariepinus were investigated to evaluate their contamination status and risks to human health. The results gave an overview of the contamination levels of these (head, body trunk and liver) fish parts. The pesticides [organochlorine (OC), organophosphorus (OP), pyrethroids (PY) and others like: guazatine, methoprene, metalaxyl and imidachloprid] concentration in the fresh and smoked body parts ranged from 0.002 to 0.221 µg/kg and 0.002 to 0.175 µg/kg, with mean concentration of 0.002–0.218 µg/kg and 0.002–0.126 µg/kg, respectively. Smoking was observed to reduce the overall pesticide concentration as follows: head (0.23 µg/kg or 17.3%), liver (0.34 µg/kg or 29.8%) and muscles (0.41 µg/kg or 27.2%). The pesticides contents were significantly lower than standard daily intake and the risk associated with consumption of the fish also showed that the fish posed no potential threat to consumers.     

Hydrogen explosion incident mitigation in steam reforming units through enhanced inspection and forecasting corrosion tools implementation

Hydrogen (H₂) explosion effects recently examined, are confirming the devastating loss scenarios to humans, environment, assets, and associated business interruption. H₂ production is a core process in refineries used in further process steps. Steam reforming of natural gas or a mix with naphtha or LPG is a common hydrogen production technique, where the latest technologies have adopted enhanced metallurgies to minimize explosion risk and the associated maintenance cost following plant degradation owing to corrosion effects. However, corrosion rates are still high in specific areas of piping and process equipment. The aim of this paper is to present a methodology based on semi-quantitative RBI modeling according to regulations by API and recent EN standards, adopting a family of linear regression forecasting models that depict the yearly corrosion rate (per corrosion loop) of a hydrogen production steam reforming unit; this is done under different operating conditions (e.g., temperature, pressure, and fluid speed), metallurgy and other related physicochemical variables. The model is based on the examination of both ultrasonic wall thinning measurements and the examination of quantitative crosslinking total corrosion effects along with the physicochemical properties prevailing in different plant corrosion loops. The outcome of the regression analysis is an expansive family of multivariable equations describing, with a defined accuracy, the yearly corrosion rate and associated lifespan forecast per corrosion loop, and per examined part. These equations were further utilized in a custom-made database that can be used as an additional loss prevention tool by the hydrogen production unit management team. Evaluation results regarding the tool efficiency are presented in the following of this paper.     

Reaction hazard and mechanism study of H2O2 oxidation of 2-butanol to methyl ethyl ketone using DSC,Phi-TEC II and GC-MS

Methyl ethyl ketone (MEK) oxidation via H₂O₂ with tungsten-based polyoxometalate catalysts has gained much attention with an ever-growing body of knowledge focusing on the development of environmentally benign processes in chemical industry. In this study, two calorimetry techniques, differential scanning calorimetry (DSC) and Phi-TEC II adiabatic calorimetry, were employed to analyze the thermal hazards associated with the 2-butanol oxidation reaction system. Hydrogen peroxide was the oxidant and a tungsten-based polyoxometalate as the catalyst. Gas chromatography-mass spectrometry was used for identification of the organic products. Important thermal kinetic data were obtained including “onset” temperature, heat of reaction, adiabatic temperature rise and self-heat rate. From DSC results, three exothermic peaks were detected with a total heat generation of approximately 1.26 kJ/g sufficiently to induce a thermal runaway. Possible reaction pathway for three stages were proposed based on both DSC and GC-MS results. One exotherm was detected by Phi-TEC II calorimeter and the pressure versus temperature profile together with the DSC and GC-MS data demonstrate the complexity of 2-butanol reaction system under both thermal screening and adiabatic conditions.     

北方县城生活垃圾填埋场的探讨

本文对垃圾填埋场垃圾处理工艺进行阐述,详细描述垃圾填埋场建设内容,并对垃圾填埋场建设的必要性进行分析。     

特殊环境中气载放射性物质的监测研究

本文对特殊环境下气载放射性物质中β放射性气体以及β放射性气溶胶做以实验,并根据后期的实验结果进行分析,详细探讨两者的测量结果,希望能为相关人士提供有效参考。     

An efficient resin for solid-phase extraction and determination by UPLCMS/MS of 44 pharmaceutical personal care products in environmental waters

• A hydrophilic resin (GCHM) was facile synthesis and characterized. • Average absolute recovery of GCHM (75.6%) performs better than Oasis^® HLB. • Detection limits of method (SPE-UPLC-MS/MS) ranged between 0.03 and 0.6 ng/L. • 22 PPCPs were determined in environmental waters ranging from 0.5 to 1590 ng/L. In this study, a hydrophilic resin named GCHM was fabricated based on poly(N-vinyl pyrrolidone-co-divinylbenzene), characterized, and applied as a solid-phase extraction (SPE) material. Up to 44 pharmaceuticals and personal care products (PPCPs) belonging to 10 classes were recovered in environmental water samples. Different variables affecting extraction, such as adsorbent amount, sample pH, and loading speed, were optimized. Under optimal conditions, the average absolute recovery of 44 PPCPs was 75.6% using GCHM, indicating a better performance than the commercial Oasis^® HLB. SPE with home-made hydrophilic polymeric sorbent followed by ultra-performance liquid chromatography and tandem mass spectrometry was validated, and the method achieved good linearity (r²>0.991, for all analytes). In addition, the method detection limits of target compounds ranged from 0.03 to 0.6 ng/L. The developed method was applied to determine PPCPs in 10 environmental water samples taken from the Yangtze River, Huaihe River, and Taihu Lake, 1 groundwater sample from Changzhou in Jiangsu Province, 1 wastewater sample from Xiamen and 2 seawater samples from the Jiulong River in Fujian Province, China. In these samples, 22 compounds were determined at levels ranging from 0.5 to 1590 ng/L.     

超高效液相色谱-三重四极杆质谱法同时分析沉积物中6种溴代阻燃剂

利用超高效液相色谱-三重四极杆质谱建立了沉积物中6种溴代阻燃剂的分析方法,同时进行了采样分析。以正己烷-二氯甲烷(体积比1∶9)为萃取剂,在100℃下用加速溶剂萃取仪提取沉积物样品,循环3次。萃取液浓缩至2.0 m L,转移至净化柱,用150 m L正己烷-二氯甲烷(体积比1∶2)淋洗。将淋洗液浓缩至近干,加入内标物,定容至1 m L后,用液相色谱-三重四极杆准确定量。方法干重检出限为0.01～0.1 ng/g;替代标回收率为75.6%～98.9%,相对标准偏差为12.0%～13.0%;目标物回收率为70.5%～99.2%,相对标准偏差为2.1%～17.0%。研究区域水体沉积物中的三(2,3-二溴丙基)异氰脲酸酯浓度为未检出～0.14 ng/g,(2,4,6-三溴苯氧基)-1,3,5-三嗪浓度为未检出～0.14 ng/g,十溴二苯醚浓度为0.81～4.36 ng/g,六溴苯浓度为未检出～0.08 ng/g,表明沉积物中新型溴代阻燃剂浓度处于较低水平。     

基于便携式氢火焰离子化检测器法测定固定污染源废气中非甲烷总烃的研究

通过实验室和固定污染源废气现场比对测试,对便携式氢火焰离子化检测器法(催化氧化法和气相色谱法)测定非甲烷总烃的检出限、转化效率、精密度和准确度等性能指标开展研究。实验室测试结果表明,便携式氢火焰离子化检测器法测定非甲烷总烃的检出下限(0.3 mg/m^3)、转化效率(98.2%)、精密度(3.49%)、准确度(-2.38%)基本满足方法技术指标的要求,但是对于催化氧化法还需重点关注其转化效率。固定污染源废气现场比对测试结果表明,便携式氢火焰离子化检测器法与实验室方法测试结果的相对准确度(33.2%)、相对误差(-9.27%~23.7%)基本能满足测试方法的测试要求,趋势性也保持一致,适用于现场测试。     

气相色谱法测定环境空气中三甲胺

采用4%聚乙二醇(PEG)-20M+1%KOHGXD-401为固定相,2m×3mm玻璃填充柱分离三甲胺,FID检测。该方法有较高灵敏度和良好的线性关系。结果表明:在柱温140℃,进样口温度180℃,检测器温度180℃,氮流量30mL/min时,平均回收率为100 3%,相对标准差为3%。