Advanced molecular-fingerprinting analysis of dissolved organic sulfur by electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry using optimal spray solvent

Molecular level characterization of dissolved organic sulfur (DOS) by electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS) is necessary for further understanding of the role of DOS in the environment. Here, ESI spray solvent, a key parameter for ion production during ESI process, was investigated for its effect on the molecular characterization of DOS by ESI-FTICR MS. 100% MeOH as spray solvent was found for the first time to remarkably enhance the ionization efficiency of the majority of CHOS-molecules in NOM, which facilitated a total of 1473 CHOS-molecular formulas with one sulfur atom to be detected. The number of CHOS-molecular formulas obtained using 100%MeOH as spray solvent increased notably over 740 in comparison with those using 50% MeOH aqueous solution (731) or 50% ACN aqueous solution (653). Moreover, due to the enhancement of ionization efficiency of DOS during ESI processes, the tandem mass spectra of the NOM CHOS-molecules could be easily obtained using 100% MeOH as spray solvent, which were hardly obtained using 50% MeOH aqueous solution as spray solvent. The results of the tandem mass spectra suggested the first discovery of organosulfates or sulfonic acids in Suwannee River NOM sample. A simple method based on 100% MeOH as ESI spray solvent for advanced molecular characterization of DOS by ESI-FTICR MS was proposed and applied, and the results revealed more molecular information of DOS in sea DOM samples.     

Effect of Humic Acid on the Bioavailability of γ-Hexachlorocyclohexane in Marsilea Minuta (L.)

Effect of various concentrations of humic acid (0.2 to 1%) on thebioavailability of -HCH in vegetative clones of theaquatic fern Marsilea minuta was studied in a staticexperimental bioassay system on different photoperiods. Additionof humic acid showed the reduction in the bioavailability of-HCH in all the photoperiods (72 hr light to 144 hrlight) at the interval of 16 hr light (L) and 8 hr dark (D) inboth aerial and submerged portion as compared to controlindicating its protective role in toxicity.     

火焰原子吸收分光光度法测定鱼内脏及河流底泥中的铜

采用火焰原子吸收分光光度法测定鱼内脏及河流底泥中的铜。鱼内脏经组织捣碎机捣成匀浆后，加硝酸消解；底泥则经氢氟酸和高氯酸消化。该方法具有灵敏度高，精密度和回收率较好等特点。     

基于实时嵌入式操作的移动环境监测系统

利用面向对象技术、多线程技术和动态链接技术在嵌入式操作Windows CE上开发了移动环境监测系统。介绍了基于实时嵌入式操作的移动环境监测系统的设计原理、系统框架及关键技术。指出在嵌入式计算机上实现移动环境监测，既可以进行在线环境监测，也可以减少开发的费用和硬件投资。该系统的特点是集成度高，体积小，反应速度快，智能化高，稳定性好和可靠性强。     

土壤中钼的形态分析方法研究

本文对土壤中有效钼的浸取条件进行最佳化，并利用提高灰化温度达到消除浸取剂对石墨炉原子吸收测定钼的影响，方法用于国标样品和武汉市区土壤样品中钼的形态分析，获得满意的分析结果。     

石墨炉原子吸收法直接测定水中钼

用石墨炉原子吸收法测定水中钼.用不带平台的热涂层石墨管,将灰化温度提高到1850℃,原子化温度定为2380℃,取得较好效果.对6个样品测定,相对标准差<10%,加标回收率在96.6～101%之间,精密度和准确度较好.     

红外法测定石油类项目中标准曲线的简化绘制

目前GB/T164 88-1996以红外分光光度法这测定石油类的有一种方法。该法用四氯代碳作莘取剂 ,四氯化碳用量大。四氯化碳是一种有毒、挥发性较强的有机溶剂。在监测该项目时 ,绘制标准曲线所用的标准储备液的配制相当复杂且形成的系统误差比较大 ,为减少误差并准确地绘制标准曲线 ,本文采取了简化配制步骤的方法来绘制曲线 ,并达到了与JDS -10 0型红外分光测油仪使用说明书中提供的方法一致的效果。     

移动通信基站电磁辐射污染分析及对策

移动通信基站发射天线产生的电磁波对环境造成电磁辐射污染，通过对沈阳移动通信公司部分基站产生的电磁辐射强度的测试，摸清了污染特点及规律，为今后环境管理规范化提供重要依据．     

Immediate prenatal diagnosis of Zellweger syndrome by direct measurement of very long chain fatty acids in chorionic villus cells

We report a gas chromatographic-mass spectrometric method which allows the very long chain fatty acids content of trophoblastic tissue to be directly measured in samples collected by biopsy between 8 and 11 weeks of gestation. This method has been successfully applied to the detection of fetal Zellweger syndrome in two pregnant women who had previously delivered affected infants. In one of them, increased concentrations of C26:0 (0.254 versus 0.108±0.035 μ/mg proteins) and C24:0 (1.32 versus 0.815±0.325 μ/mg proteins) in trophoblast indicated that the fetus had Zellweger syndrome, a diagnosis confirmed by pathological findings after abortion. In the second case, the pregnancy was allowed to proceed, on the basis of normal concentrations of very long chain fatty acids in trophoblastic tissue, and its outcome was actually a healthy newborn.     

氢化物发生一原子荧光光谱法测定气田废水中的痕量砷

采用氢化物发生－原子荧光光谱法测气田废水中的痕量砷。方法有取样量少，操作简单、灵敏度高、准确度高、重现性好等优点。砷的测定线性范围为1～200ng/mL，方法的检出限为0．0453ng/mL，相对标准偏差小于等于1．6％，加标回收率在96．0％～97．7％范围内。测定密码标样与气田废水中的痕量砷，获得了满意的结果。