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应用原子吸收法测定水样中的总铬,在不同条件下对空白样品、标准样品和实际样品进行试验分析,进一步验证了方法的准确度和精密度,加标回收率在96.8%-103%之间,相对标准偏差为2.1%。试验表明,该方法准确可靠,实际操作具有可行性,适用于工业废水和受污染地表水中总铬的测定。 相似文献
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将样品中的颗粒物分离出来后,向样品中加入适量硝酸银,除去生成的氯化银沉淀,再将预先分离的颗粒物合并到水样中,混匀后测定。经过这样处理,既去除了水样中的Cl-,又保留了水样中原来的组份,保证了COD测定结果的准确性。 相似文献
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将样品中的颗粒物分离出来,向样品加入适量硝酸根,除去生成的氯化银沉淀,再将预先分离的颗粒物合并到水样中,混匀后测定,经过这样处理,既去除了水样中的Cl,以保留了水样中原来的组份,保证了COD测定结果的准确性。 相似文献
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用F—732型冷原子吸收测汞仪与改良的FJ-1型金膜富集解吸器组配,对环境样品中痕量总汞进行了测定.系统采用了闭环内气源气路,提高了富集效率和方法的检测限(从0.1μg/L提高到0.003μg/L),不仅可用于高汞含量水样的测定,还可用于清洁样品中痕量汞的测定. 相似文献
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离子色谱法测定环境水样阴离子处理方法的试验 总被引:4,自引:0,他引:4
本文研究了离子色谱法测定环境水样中阴离子时样品的一般处理方法。该方法以固体无水碳酸钠处理水样并以酚酞指示剂指示处理的终点,以邻苯二甲酸除去样品碱性干扰,以活性炭吸附水样中的有机物和酚酞指示剂。研究测试和监测实践的结果表明,该方法应用于环境监测简单可靠。 相似文献
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对空气中甲醛测定的采样方法进行了探讨 ,分别用水和稀硫酸作吸收液对空气甲醛进行采样研究。结果表明 ,用 0 .0 0 5mol LH2 SO4 作吸收液的采样方法 ,可有效、稳定地延长样品的保存时间 ,且又符合方法灵敏度和精密度的要求。 相似文献
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通过测定Cr^3+、Cr2O7^2-和Cu^2+吸收曲线及标准水样的COD值,研究了Cu^2+对分光光度法测定COD的影响。结果表明,可改变吸收波长和量程消除较高质量浓度Cu^2+对COD测定值产生的明显影响。当水样Cu^2+质量浓度超过400mg/L时,须将水样稀释后采用低量程法进行测定。 相似文献
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本文结合TOC总有机碳分析仪和SSM固体样品燃烧装置各自的特点,探索了测定环境水样中包含全部颗粒态有机碳的测定方法.此方法能够全面反映环境水样中总有机碳的含量 相似文献
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建立了吹脱-电导法测定水和污水中的氨氮的方法。该方法是在90℃温度下,以气体将水样中氨氮吹出,用5mmol/L硫酸吸收,吸收液电导率的方法,在一定浓度范围内与氨氮吹出量成正比。测定标准样品的相对标准差和相对误差均为2.7%,方法的精密度和准确度均较好。根据该方法原理研制的氨氮在线自动分析仪测定自行配制的氨氮标准溶液,相对误差在2.8%以内,测定值准确可靠,最低检出限为0.1mg/L,两台样机分别用于黄河边国家水质自动站测定地表水和济南水质净化一厂测定污水,经过约5个月的运转,情况良好。 相似文献
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Sezin Erarpat Gözde Özzeybek Dotse Selali Chormey Fatih Erulaş Fatma Turak Sezgin Bakırdere 《Environmental monitoring and assessment》2017,189(10):528
Polycyclic aromatic hydrocarbons are known for their carcinogenic and mutagenic effects on human health. This therefore calls for the regulation of their concentrations in air, water, and soil. Naphthalene as the simplest in structure of the polycyclic aromatic hydrocarbons is mainly used as a starter material for other chemicals but also has impacts on human health. A method is therefore proposed for the determination of naphthalene in water samples by gas chromatography mass spectrometry after liquid-liquid extraction. The extraction method was optimized to improve the extraction output, thereby lowering the limit of detection. The limits of detection and quantification obtained for naphthalene were 4.4 and 14.6 ng mL?1, respectively. Deuterated anthracene was used as internal standard to enhance the precision of the method, for which a relative standard deviation of 4.3% was obtained. The percent recovery of naphthalene obtained from tap water was ranged between 93.8 and 102.2. 相似文献
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Li Z Mulholland JA Romanoff LC Pittman EN Trinidad DA Lewin MD Sjödin A 《Journal of environmental monitoring : JEM》2010,12(5):1110-1118
Non-occupational inhalation and ingestion exposure to polycyclic aromatic hydrocarbons (PAHs) has been studied in 8 non-smoking volunteers through personal air sampling and urinary biomonitoring. The study period was divided into 4 segments (2 days/segment), including weekdays with regular commute and weekends with limited traffic related exposures; each segment had a high or low PAH diet. Personal air samples were collected continuously from the subjects while at home, at work, and while commuting to and from work. All urine excretions were collected as individual samples during the study. In personal air samples, 28 PAHs were measured, and in urine samples 9 mono-hydroxylated metabolites (OH-PAHs) from 4 parent PAHs (naphthalene, fluorene, phenanthrene and pyrene) were measured. Naphthalene was found at higher concentrations in air samples collected at the subjects' residences, whereas PAHs with four or more aromatic rings were found at higher levels in samples taken while commuting. Urinary OH-PAH biomarker levels increased following reported high inhalation and/or dietary exposure. On days with a low PAH diet, the total amount of inhaled naphthalene during each 24-hour period was well correlated with the amount of excreted naphthols, as was, to a lesser extent, fluorene with its urinary metabolites. During days with a high dietary intake, only naphthalene was significantly correlated with its excreted metabolite. These findings suggest that this group of non-occupational subjects were exposed to naphthalene primarily through indoor air inhalation, and exposed to other PAHs such as pyrene mainly through ingestion. 相似文献
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Li X Li P Yan L Chen J Cheng T Xu S 《Journal of environmental monitoring : JEM》2011,13(11):2988-2993
Atmospheric polycyclic aromatic hydrocarbons (PAHs) mainly originate from incomplete combustion or pyrolysis of materials containing carbon and hydrogen. They exist in gas and particle phases, as well as dissolved or suspended in precipitation (fog or rain). Current studies in atmospheric PAHs are predominantly focused on fog and rainwater samples. Some sampling difficulties are associated with fog samples. This study presented the first observation of the characteristics of PAHs in fog samples using a solid phase microextraction (SPME) technique. Eighteen fog samples were collected during ten fog events from March to December 2009 in the Shanghai area. PAHs were extracted by SPME and analyzed by gas chromatography-mass spectrometry (GC-MS). As the compounds were partially soluble in water, with solubility decreasing with increasing molecular weight, low molecular weight (LMW) PAH compounds were universally found in the fog water samples. Naphthalene (NaP), phenanthrene (Phe), anthracene (Ant) and fluoranthene (Flo) were dominant compounds in fog water. The total PAH concentration in fog water ranged from 0.03 to 6.67 μg L(-1) (mean of 1.06 μg L(-1)), and was much higher in winter than in summer. The concentration of PAHs in fog or rain water decreased after undergoing a pre-rain or pre-fog wash. The average concentration of PAHs was higher in fog than in rain. Diagnostic ratio analysis suggested that petroleum and combustion were the dominant contributors to PAHs in urban Shanghai. Backward trajectories were calculated to determine the origin of the air masses, showing that air masses were mostly from the northeast territory. 相似文献
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Gabriela V. Martins Susana Martins Anabela O. Martins M. Clara P. Basto Gabriela Ventura Silva 《Environmental monitoring and assessment》2013,185(8):6447-6457
In the last decade, the development of novel analytical methodologies enabled the identification of several environmental pollutants responsible for health problems associated with indoor exposure. Polycyclic aromatic hydrocarbons (PAHs) are among the potential hazardous chemicals present in ambient air. Due to their bioaccumulation potential and carcinogenic/mutagenic effects, 16 PAHs are currently listed as priority air pollutants. The main goal of this work was to implement a new and simple method for sampling and determination of PAHs in air by using a thermal desorption (TD) technique followed by gas chromatography coupled with mass spectrometry analysis. A detailed study was carried out to optimise the experimental method in each of its phases, including (active) sampling, TD and chromatographic analysis. The results demonstrate that this approach allowed the detection and quantification of the six more volatile PAHs, namely, naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, and anthracene. Acceptable precision and good linearity over the explored range were obtained. No carry-over was observed during experimental tests and the method provided a reproducible answer. The applicability of the novel methodology was tested in real environment, namely, on the roof of a building in an urban area, in a domestic kitchen and in a collective car garage. The method enabled the identification of two PAHs in the field samples, specifically, naphthalene (two rings) and phenanthrene (three rings). With regard to PAHs sample composition, the most abundant PAH found, in the three different locations, was naphthalene, accounting for about 84–100 % of the total PAH mass detected. 相似文献
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燃煤电厂烟气降温过程中多环芳烃分布特征 总被引:1,自引:1,他引:0
分别以燃用褐煤与烟煤无烟煤的2个电厂为例,研究2个电厂烟气降温过程中多环芳烃的分布及转化特征。研究表明,萘、菲、苯并[a]蒽和苯并[a]芘4种多环芳烃在烟气降温过程中呈过渡分子状态,在适当的条件下,存在相互转化的可能性;萘、菲、苯并[a]蒽和苯并[a]芘在不同的电厂随飞灰粒径变化所表现出来的吸附特性不同,颗粒的粒度影响多环芳烃的形成与吸附。在烟气降温过程中飞灰表面吸附的萘、菲、苯并[a]蒽和苯并[a]芘含量随着飞灰粒径的变小呈现出逐渐增加的趋势。 相似文献