玻璃注射器对顶空气相色谱法分析苯系物的误差原因分析

按GB11890—89顶空气相色谱法分析苯系物时，发现重复性和分割水平样品平行性较差，经仔细分析，是由于使用普通玻璃注射器造成的。为避免此类误差，建议顶空气相色谱法分析时，使用带特氟龙顶端推杆的气密性注射器。     

固相微萃取气相色谱法测定水样中的苯胺、吡啶

应用PDMS/DVB固相微萃取探头,结合GC/FID测定水中的苯胺、吡啶.优化了萃取温度、萃取平衡时间、pH等条件.该方法对苯胺和吡啶的检测限分别为0.050、0.065 mg/L,相对标准偏差6.44%～8.67%,具有快速、准确和方便等优点.     

气质联用分析加硫酸化污泥中的有机酸

分别采用两种前处理方法分离富集加硫酸化污泥中的有机酸.方法一,利用阴离子交换树脂分离富集有机酸,在不洗脱的情况下直接和乙醇进行酯化反应,然后进行气质联用分析;方法二,利用活性炭纤维吸附型固相微萃取(ACF-SPME)的方法,顶空萃取分离后进行气质联用分析.两种方法的分析结果都未检测到酸化污泥中存在短链的有机酸,只检测到个别长链的和带苯环结构的有机酸.     

气相色谱法测定水中的2，4-二硝基氯苯

采用苯萃取,HP-624 30 m×0.53 mm×3.00 μm大口径毛细管柱分离,电子捕获检测器(ECD)检测2,4-二硝基氯苯,得到了良好的分离效果、较宽的线性关系和较高的灵敏度.     

Impact of cadmium and nickel on ion homeostasis in the yeast Schizosaccharomyces pombe

Abstract

Toxicity of heavy metals to living organisms is a worldwide research topic. Although, much has been discovered about cadmium and nickel impact on biological systems, a lot still remains unclear. We used inductively coupled plasma – optical emission spectroscopy to address the question of the effect of two different heavy metals nickel, and cadmium on intracellular ion balance. Increase or decrease of the content of several essential cations including Ca²⁺, Na⁺, K⁺, Mg²⁺, Cu²⁺, Fe³⁺ in the yeast Schizosaccharomyces pombe was determined. Our results revealed that the cell exposure to high nickel and cadmium concentrations led to significant elevation of Ca²⁺, Na⁺, Mg²⁺, Cu²⁺, Fe³⁺ levels in the yeast cell, while the content of K⁺ decreased. Correlation analyses showing in the presence of nickel and cadmium strong positive correlation among each tested element (Ca²⁺, Na⁺, Cu²⁺, Mg²⁺ and Fe³⁺) except for K⁺, demonstrate the significant impact of heavy metal treatment to ion homeostasis of the cell. Our data indicate that acute nickel and cadmium contamination leads to substantial ionome misbalance in yeast.     

Investigation on the influence of methanol on adsorption and leaching of pesticides with soil column liquid chromatography

The effect of methanol of low concentration on adsorption and leaching of atrazine and tebuconazole was studied in this paper. The adsorption coefficients and the retardation factors (R^m) of pesticides on EUROSOIL 3# log-linearly decreased as volumetric fraction of methanol (f^c) was increased in the binary solvent mixtures of methanol and water. These data are consistent with solvophobic theory formerly outlined for describing the adsorption and transport of hydrophobic organic chemicals from mixed solvents. Nevertheless, the adsorption of these pesticides in soil–water system slightly increased when the soil was pre-washed with methanol in comparison with that pre-washed with water (pure water system). Furthermore, their adsorption coefficients were still higher in binary solvent systems with methanol of very low concentrations, i.e. f^c<0.03 for atrazine and f^c<0.01 for tebuconazole, than those in pure water system. The adsorption coefficients (logK^w) of atrazine and tebuconazole predicted by solvophobic theory were 0.5792 and 1.6525, respectively, and their experimental logK^w were 0.3701 and 1.6275 in pure water system. Obviously, the predicted logK^w of the two pesticides was higher than the experimental log K^w in pure water system. The predicted K^w and the retardation factor (R^w) in pure water system by solvophobic theory are thus possibly inaccurate.     

基于紫外光谱分析的腐殖质混凝控制

腐殖质是水溶性天然有机物(DOM)的主要成分,对水处理过程有重要影响.为探究利用紫外光谱分析实现饮用水处理在线混凝控制的可行性和理论基础,以含腐殖酸和高岭土配水为实验对象,通过烧杯实验考察了不同水质条件对PACl混凝剂最佳投加量的影响,研究了SUVA_(254)和光谱特征斜率与混凝效果的相关性,利用排阻色谱分析了紫外光谱斜率与水体有机物组分之间的关系.结果表明,混凝剂最佳投加量与DOM浓度呈正比关系,两者计量学关系(以Al/DOC计)为0.61mg·mg~(-1).随混凝剂投加量的增加,腐殖酸溶液的SUVA_(254)从8.9 L·(mg·m)~(-1)下降并稳定至2.0 L·(mg·m)~(-1),有机物去除率与SUVA_(254)值呈正相关.光谱斜率与SUVA_(254)的变化趋势一致,且S_(275~295)与SUVA_(254)线性相关最优(R2=0.81).排阻色谱结果表明,混凝优先去除DOM中的腐殖质组分,S275~295与有机物中腐殖质组分对总UVA_(254)的占比存在明显的线性相关,光谱斜率测定对实现饮用水混凝过程的控制有重要意义.     

SPME-GC/MS法测定垃圾渗沥液中双酚A

建立了固相微萃取-气相色谱质谱联用法测定垃圾渗沥液中双酚A的方法,并用于广州大田山垃圾渗沥液中双酚A含量的测定。对影响萃取的参数进行了优化,实验选用涂层厚度为85μm聚丙烯酸酯(PA)萃取纤维,在搅拌速度为1200r/min、NaCl浓度为20%、pH2.0和室温条件下萃取60min。方法的线性范围为0.1～100μg/L,检出限为0.03μg/L,精密度为6.6%。应用本方法监测了广州大田山垃圾渗沥液中BPA的含量在生物法处理过程中的变化情况。     

气相色谱法测定地下水的乙醇和单环芳香烃

探讨了同时测定地下水中乙醇和单环芳香烃的顶空气相色谱方法。水中的乙醇和微量芳香烃经过顶空提取后,应用HP-5毛细管色谱柱,利用分流与不分流进样口进样,同时采用程序升温方式进行GC分析,以保留时间定性,外标法定量。研究结果表明,乙醇、苯、甲苯、乙苯、对二甲苯和间二甲苯、邻二甲苯的线性范围分别为0.38~189.36mg/L、6.0~1500.0μg/L、6.0~1500.0μg/L、6.0~1500.0μg/L、12.0~3000.0μg/L和6.0~1500.0μg/L,最低检出浓度为137.14μg/L、0.62μg/L、0.55μg/L、0.51μg/L、0.51μg/L和0.59μg/L,水样加标回收率为91.91%L~106.35%L,RSD为2.79%L~3.76%L。表明该方法一次性完成地下水中乙醇和单环芳香烃的分离和测定,分析时间仅为15min,操作简便、灵敏。     

气相色谱法测定建材市场空气中的苯、甲苯和二甲苯

采用活性炭吸附—CS2解析毛细管气相色谱法,对建材市场空气中的苯、甲苯、二甲苯进行了测定。采用活性炭管采集样品,经CS2解析,FID做检测器,考察了苯、甲苯、二甲苯的线性关系。经实验测得解吸率在90%以上,苯、甲苯、二甲苯的加标回收率在96.6%~102.1%,线性方程的相对系数在0.999以上。该方法采样装置体积小、噪音低、操作简便,适用于同时进行苯、甲苯、二甲苯的快速测定。