空气中甲醛测定方法综述

大气环境甲醛污染主要来源于各种有机物的不完全燃烧(如汽油、柴油机的排气)及呋喃、树脂、粘合剂等工业排放。室内甲醛污染主要有建筑材料和脲醛树脂的家俱制品。甲醛对人体的危害除了引起刺激性慢性疾病外,甲醛与盐酸反应生成的二氯甲醚可致癌。随着室内和大气环境中低浓度甲醛监测的需要,采样方法有了新的开发,分析方法也有较大的进展,目前应用较多的仍是化学法和仪器法。     

乙酰丙酮光度法测定甲醛方法的改进

用乙酰丙酮溶液将CODcr反应管制成标准反应管,CODcr消解器加热回流30min,DR／2010分光光度计比色测定甲醛含量。方法精密度、准确度满足甲醛测定的分析要求。     

乙酰丙酮分光光度法测定新装修住宅室内空气中的甲醛

对乙酰丙酮分光光度法测定室内空气中甲醛的方法进行了优化,同时对北京市11户部分新装修居室室内空气中的甲醛含量进行了测定.结果表明,有8户住宅超过了我国室内空气质量标准GB/T18883-2002规定的甲醛最高容许质量浓度0.10 mg/m3.     

乙酰丙酮分光光度法测定新装修住宅室内空气中的甲醛

对乙酰丙酮分光光度法测定室内空气中甲醛的方法进行了优化,同时对北京市11户部分新装修居室室内空气中的甲醛含量进行了测定.结果表明,有8户住宅超过了我国室内空气质量标准GB/T18883-2002规定的甲醛最高容许质量浓度0.10 mg/m3.     

3种蕨类植物对甲醛的净化能力

实验以铁线蕨、鸟巢蕨和肾蕨为材料,采用烟熏法测定了其对甲醛的净化能力以及电导率、丙二醛含量、超氧物歧化酶活性和过氧化物酶活性等生理指标。结果表明,这3种蕨类植物对甲醛吸收能力从大到小是鸟巢蕨 > 肾蕨 > 铁线蕨。3种蕨类植物在受到甲醛胁迫后出现不同程度的伤害,其中质膜透性均有上升,铁线蕨上升最大,其次是肾蕨、铁线蕨;丙二醛含量,超氧物歧化酶活性都有所上升;过氧化物酶活性中铁线蕨是逐渐降低,而鸟巢蕨、肾蕨是逐渐上升。通过测定以上4个指标得出鸟巢蕨对甲醛的抗性最大,其次是肾蕨、铁线蕨。     

两种空气自动监测系统的比较

国产长光程空气自动监测系统是中国自行研制的更为先进、更具自动化的系统，24h点式仪器是老式空气检测仪器，对这两种新、老仪器的比较可以看出在运行过程中的利弊。     

甲醛工业废水的处理方法及研究进展

甲醛废水是一种难处理的工业废水,因此介绍了利用氧化法、生物降解法、缩合／沉淀法及物理处理法对其处理的方法,并对技术参数进行了说明和比较,对处理技术的发展趋势进行了探讨。     

水生植物总氮测定中两种消化方法的比较

水生植物在人工湿地污水净化过程中起着非常重要的作用,植物组织中氮、磷的含量是考察人工湿地净化污水效能的一个重要指标。采用经典的Kjeldahl（凯氏）消化法和H2SO4—H2O2消化法测定了人工湿地植物体中总氮含量,分析了两种消化方法各自的优缺点,并应用SPSS统计软件对两种方法测得的数据进行统计检验。其结果表明,两种方法测得的总氮含量具有显著性差异。应根据不同的实验要求选择适宜的测定方法。     

甲醛降解细菌的分离鉴定和降解效果测定

从某化工厂污水处理系统的活性污泥中分离纯化得到一株能降解甲醛的革兰氏阳性菌,对其进行形态及生理生化特性测定,提取并纯化其基因组DNA,通过PCR扩增菌株的16S rDNA,测序结果表明,该菌株和苏云金芽孢杆菌的同源性为100%。在含1.2 μL/mL的甲醛的培养基上培养该菌36 h后,甲醛降解去除率达到72％以上。     

水中总铁两种测定方法的比较

环境监测实验室常使用不同方法进行重复检测作为检测结果质量保证的手段之一。据此对测定水中总铁的两种方法 -邻菲啰啉分光光度法和火焰原子吸收法在校准曲线和检出限、方法精密度和准确度等进行了全面比较,得出两者校准曲线相关性均较好,检出限均为0.03 mg/L,精密度RSD均小于5%,加标回收率均在90%～105%。两者的测定结果无显著性差异。     

测定地表水及饮用水中硫酸盐的两种方法探讨

通过比较两种监测分析方法,分析了测定硫酸盐分光光度法的影响因素、存在问题,以及火焰原子吸收法的优点,提出对不同浓度范围的硫酸盐,宜采用合适的分析方法,以减小测定的误差,提高测定结果的准确性和科学性。     

高锰酸钾改性球形中孔炭的甲醛吸附性能

采用球形中孔炭为载体,通过浸渍法担载高锰酸钾（KMnO4）制备高容量甲醛吸附剂。通过低温氮气吸附法、扫描电镜(SEM)、X射线光电子能谱(XPS)表征了球形中孔炭的孔结构及表面化学,并采用固定床测试了相应的球形中孔炭的动态甲醛吸附性能。实验结果表明：经过KMnO4浸渍改性后,球形中孔炭保持良好的球形度,并保留一定的比表面积和孔容,有利于甲醛的扩散以及甲醛与吸附活性位的接触;同时,表面C—O、C=O等含氧官能团数量增加,有效提高了甲醛的吸附性能。在KMnO4浓度为30%时性能最佳,吸附穿透容量和饱和容量分别为30.55 mg·g-1和66.04 mg·g-1,是未改性球形中孔炭的5.2倍和3.4倍。因此,KMnO4改性是提升球形中孔炭甲醛吸附性能的有效手段。     

新装修居室甲醛污染的危害与控制技术

综述了新装修居室的甲醛对人体健康的危害,通过分析污染的来源,提出了切实可行的控制方法。     

两种方法测定固体废物中的总氮

对固体废物中总氮含量的测定方法进行了研究，用修正的凯氏法消解作比较、凯氏定氮仪定氮，纳氏试剂分光光度法和滴定法分别测定铵态氮，对国家标准土样GSS-7及实际的不同含氮固体废物样舄的测定值进行F检验和t检验，结果表明，两种测定方法间的精密度与准确度均无显著性差异，修正的凯氏法-纳氏试剂分光光度法及修正的凯氏法-滴定法均适用于测定固体废物中的总氮。     

传统手工法和自动监测法检测空气中颗粒物的对比

分别运用传统的中流量颗粒物采样器和RP1400 a自动测尘仪,对空气中颗粒物（TSP和PM10）进行同步采样检测,结果表明,两种方法的检测结果存在着明显的系统偏差,前者的检测结果较后者偏高。     

Formaldehyde emission—Comparison of different standard methods

The emission of formaldehyde is an important factor in the evaluation of the environmental and health effects of wood-based board materials. This article gives a comparison between commonly used European test methods: chamber method [EN 717-1, 2004. Wood-based panels—determination of formaldehyde release—Part 1: formaldehyde emission by the chamber method. European Standard, October 2004], gas analysis method [EN 717-2, 1994. Wood-based panels—determination of formaldehyde release—Part 2: formaldehyde release by the gas analysis method, European Standard, November 1994], flask method [EN 717-3, 1996. Wood-based panels—determination of formaldehyde release—Part 3: formaldehyde release by the flask method, European Standard, March 1996], perforator method [EN 120, 1993. Wood based panels—determination of formaldehyde content—extraction method called perforator method, European Standard, September 1993], Japanese test methods: desiccator methods [JIS A 1460, 2001. Building boards. Determination of formaldehyde emission—desiccator method, Japanese Industrial Standard, March 2001 and JAS MAFF 233, 2001] and small chamber method [JIS A 1901, 2003. Determination of the emission of volatile organic compounds and aldehydes for building products—small chamber method, Japanese Industrial Standard, January 2003], for solid wood, particleboard, plywood and medium density fiberboard.The variations between the results from different methods can partly be explained by differences in test conditions. Factors like edge sealing, conditioning of the sample before the test and test temperature have a large effect on the final emission result. The Japanese limit for F **** of 0.3 mg l⁻¹ (in desiccator) for particleboards was found to be equivalent to 0.04 mg m⁻³ in the European chamber test and 2.8 mg per 100 g in the perforator test. The variations in inter-laboratory tests are much larger than in intra-laboratory tests; the coefficient of variation is 16% and 6.0% for the chamber method, 25% and 3.5% for the gas analysis method and 15% and 5.2% for the desiccator method.     

Comparison of Nonmethane Organic Compound Concentration Data Collected by Two Methods in Atlanta

Title I of the Clean Air Act Amendments of 1990 calls for “enhanced monitoring” of ozone, which is planned to include measurements of atmospheric non-methane organic compounds (NMOCs). NMOC concentration data gathered by two methods in Atlanta, Georgia during July and August 1990 are compared in order to assess the reliability of such measurements in an operational setting. During that period, automated gas chromatography (GO) systems (Field systems) were used to collect NMOC continuously as one-hour averages. In addition, canister samples of ambient air were collected on an intermittent schedule for quality control purposes and analyzed by laboratory GC (the Lab system). Data from the six-site network included concentrations of nitrogen oxides (NOX), carbon monoxide (CO), ozone, total NMOC (TNMOC), and 47 identified NMOCs. Regression analysis indicates that the average TNMOC concentration from the Lab system is about 50 percent higher than that from the Field system, and that the bulk of the difference is due to unidentified NMOCs recorded by the Lab system. Also, there are substantial uncertainties in predicting a single Field TNMOC concentration from a measured Lab concentration. Considering individual identified NMOCs, agreement between the systems is poor for many olefins that occur at low concentrations but may be photochemically important. Regressions of TNMOC against CO and NOX lead to the conclusion that the larger unidentified component being reported by the Lab system is not closely related to local combustion or automotive sources.