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811.
为更好地对县域环境进行监测,确保县级环保事业的有效推进,就离子色谱仪在县级环境监测中的应用、仪器的维护与保养等进行了分析与论述。  相似文献   
812.
A method of size exclusion chromatography coupled with ultraviolet spectrophotometry and off-line graphite furnace atomic absorption spectrometry was developed to assess the complexation properties of iron (Fe) and humic acid (HA) in a water environment. The factors affecting the complexation of Fe and HA, such as ionic strength, pH, temperature and UV radiation, were investigated. The Fe-HA complex residence time was also studied. Experimental results showed that pH could influence the deprotonation of HA and hydrolysis of Fe, and thus affected the complexation of Fe and HA. The complexation was greatly disrupted by the presence of NaCl. Temperature had some influence on the complexation. The yield of Fe-HA complexes showed a small decrease at high levels of UV radiation, but the effect of UV radiation on Fe-HA complex formation at natural levels could be neglected. It took about 10 hr for the complexation to reach equilibrium, and the Fe-HA complex residence time was about 20 hr. Complexation of Fe and HA reached a maximum level under the conditions of pH 6, very low ionic strength, in the dark and at a water temperature of about 25°C, for 10 hr. It was suggested that the Fe-HA complex could form mainly in freshwater bodies and reach high levels in the warm season with mild sunlight radiation. With changing environmental parameters, such as at lower temperature in winter or higher pH and ionic strength in an estuary, the concentration of the Fe-HA complex would decrease.  相似文献   
813.
Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were analysed in surface soil samples collected in 2001–2002 at an open urban area of Madrid. In order to obtain representative samples, three collection points at the site were chosen. The most abundant PAHs and PCBs were phenanthrene, fluorene, pyrene, chrysene and benzo[a]pyrene and hexa- and heptachlorinated PCBs, respectively. The sum of selected PAHs (13 compounds) and PCBs (15 congeners) averaged 1 and 0.1?µg?g?1, respectively. PCB levels in winter were 2–10 times higher than summer ones, while seasonal variation for most of PAHs were not observed. Good correlations among all PCBs were found. Five PAHs were also well correlated.  相似文献   
814.
水和废水中酞酸酯类化合物液相色谱分析方法验证   总被引:3,自引:0,他引:3  
为了对水和废水中酞酸酯类化合物液相色谱分析方法进行验证实验。对方法的最低检出限、校准曲线、密码样和实际水样精密度、准确度,进行了全面的测定分析,三种酞酸酯类化合物的最低检出限为:5.01~17.80ng,相对标准偏差小于4.2%,加标回收率在84.1%~98.9%范围内。  相似文献   
815.
Penoxsulam is a triazolopyrimidine sulfonamide group of rice herbicide. The phototransformation of penoxsulam was studied under UV light (λmax ≥ 290 nm) and sunlight in aqueous methanol and acetonitrile solvent system using TiO2 as sensitizer. The rate of photodegradation of penoxsulam in different solvent systems followed first-order kinetics and calculated half-lives was found to be in the range of 51.89–73.41 h and 62.70–97.09 h for UV light and sunlight respectively in the presence or absence of sensitizer. From this study, a total of six photoproducts were identified and characterized on the basis of Q-Tof micromass spectral data. The plausible mechanism of phototransformation involved were hydrolysis, photo oxidation of the sulfonamide group, breaking of sulfonamide bond, loss of amino and sulfonic acid group.  相似文献   
816.
建立了用气相色谱法测定废气中丙酮和丁酮的方法。废气中丙酮和丁酮活性炭吸附,二硫化碳解吸,NNOWAX毛细管柱分离,直接进样分析,氢火焰离子化检测器检测,时间定性,峰面积定量,其丙酮回收率为91.6%~103.5%,丁酮回收率为90.2%~104.3%,当采样体积为30L,丙酮和丁酮最低检出质量浓度为0.001mg/m3。本方法前处理简便,分离度好干扰少,分析灵敏度高,有机试剂使用量少,满足环境分析要求。  相似文献   
817.
吴俐 《化工环保》2001,21(1):41-44
用苯萃取浓缩煤焦油废水中的联苯和菲,然后用薄涂柱气相色谱法进行测定。试验表明:该法具有色谱柱温低、快速、准确等特点。  相似文献   
818.
探讨了离子色谱法测定地表水中氟化物的影响因素:水质样品的采集保存;水质样品所含成份;实验用水、试剂纯度、实验器皿的影响;使用离子色谱仪测定过程中对氟化物的影响。认为应切实采取措施,消除干扰。  相似文献   
819.
气相色谱法测定气体中的二溴甲烷   总被引:1,自引:0,他引:1  
建立了一种简便快速测定空气中二溴甲烷的方法,即空气中的二溴甲烷经Tenax管吸附,TJ-618热解析仪解析,电子捕获检测器检测,该法线性关系良好,其精密度及回收率均符合方法学要求,方法结果简单、快速、准确、可靠。  相似文献   
820.
以顶空气相色谱法直接测定聚苯乙烯食品包装材料固体试样中的苯,甲本、对二甲苯和苯乙烯,最小检出量为10-10^10g,回收率为97.6%-102.5%。该法基体干扰小、操作简便。  相似文献   
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