固定污染源废气中苯系物的测定方法研究

基于标准DB31/933-2015附录E固定污染源废气苯系物的测定气袋采样-气相色谱法进行了验证探究实验,该方法标准曲线线性良好,相关性系数均高于0.998;重复性准确度测定情况良好,苯系物各组分RSD%在0.9%～5%之间,加标回收率在80%～100%之间。该方法操作简单、准确度高、精密度好,适用于固定污染源废气中苯系物的测定;但是由于气体样品本身性质的不稳定和考虑到气袋质量参差不齐,采集的样品应尽快分析,根据DB31/933-2015附录E要求,样品应在12 h内完成分析。     

食品包材印刷油墨中苯系物含量测定研究

建立了溶剂提取气相色谱/质谱法测定油墨中苯系物含量的方法.以甲醇提取样品苯系物,气相色谱质谱联用法测定,外标法定量,同时检测样品中8种苯系物含量.在优化的实验条件下,该方法的线性关系良好,线性范围(0.1～50)μg/mL加标回收率在92.69％～101.52％之间,相对标准偏差在3.16％～5.06％之间.该方法操作简单,准确度和精密度较高,是一种检测油墨产品中苯系物含量的有效方法.     

气相色谱法测定污染源中的苯系物

采用活性炭采样管富集气污染源中的苯系物，以二硫化碳为解吸剂，经毛细管柱测定样品中的苯系物，以保留时间定性，峰面积定量。通过对样品的采样和前处理方法法方法进行了不同条件的探讨，得出了最佳的实验条件。本方法中苯系物各组分线性方程的相关系数均大于0．999，方法的最低检出浓度在15-39μg/m^3，加标回收率在95.3～101％之间，相对标准偏差小于4．5％（n=6），能满足实际工作的需要。     

聚醋酸乙烯酯胶粘剂中苯系物含量测定

建立了气相色谱内标法测定家具聚乙酸乙烯酯胶粘剂中苯系物含量的方法。样品中苯系物经甲醇提取、离心,上清液用60 m EN-20色谱柱分离,气相色谱检测,内标法定量。优化条件下苯系物回收率在96.84%~103.86%,相对标准偏差(RSD)为0.79%~2.28%,定量下限2.4~2.9 mg/L。本方法操作简单,准确度和精密度较高,是一种检测聚乙酸乙烯酯胶粘剂产品中苯系物含量的有效方法。     

气相色谱测定汽油苯含量的不确定度评定

通过分析气相色谱法测定汽油中苯含量的操作流程,对汽油中的苯含量测量结果的不确定度进行了评定.不确定度主要来源于相对定量校正因子、样品中添加内标物丁酮的体积、样品的体积、样品中苯与内标物丁酮面积的平均值之比、标准物质苯和丁酮的纯度以及气相色谱自身参数和微量进样器引入的不确定度。     

吹扫捕集气相色谱法测定水性涂料中的苯系物

建立了吹扫捕集气相色谱法测定水性涂料中8种苯系物的分析方法,对色谱条件、吹扫条件等进行了探讨,同时对分析参数如线性相关性、相对标准偏差、最低检出限及加标回收率进行了评价.结果表明:采用吹扫捕集气相色谱法,在2.5～ 50.0 μg/L范围内,8种苯系物的质量浓度和峰面积呈良好的线性关系;对加标浓度为5.0μg/L的涂料样品平行测定7次,其相对标准偏差为1.8％～4.3％;水性涂料样品的加标回收率在88.3％ ～ 107％之间;最低检出限在0.50～1.0 μg/L之间.     

塑胶涂料中苯系物的测定方法研究

建立了分离分析塑胶漆中有害物质苯系物(苯、甲苯、二甲苯、乙苯)的气相色谱方法。结果表明,本方法对塑胶涂料实际样品中苯系物的平行检测结果的相对标准偏差在1.7%～2.1%,加标回收率在98.6%～99.0%,准确度和精确度均较好,可以满足实际样品的分析。     

苯氧乙醇标准物质的纯度分析方法及不确定度评定

采用质谱(MS)和核磁共振谱(NMR)对原料苯氧乙醇进行定性分析,优化并建立了液相色谱法及气相色谱法测定苯氧乙醇,纯度为99.3％.以甲醇为基体溶液,采用重量-容量法制备苯氧乙醇标准物质.以液相色谱(紫外法、示差法)两种方法进行定值,并做了均匀性检验和稳定性跟踪.建立不确定度评定方法,标准物质特性值为99.3(±1.1) μg/mL(k=2).苯氧乙醇标准物质具有溯源性和准确性,对于化妆品中防腐剂苯氧乙醇含量的准确测定及监控具有重要意义.     

罐采样/气相色谱-质谱法测定页岩气中的苯系物含量

建立了罐采样/气相色谱-质谱法测定页岩气中苯系物含量的分析方法。用内壁惰性化处理的不锈钢罐采集样品,经冷阱浓缩、热解析后,进入气相色谱分离,用质谱检测器进行检测。通过与标准物质质谱图和保留时间比较定性,外标法定量。全扫描模式下,苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯的检出限为0.9μg/m3、1.0μg/m3、1.2μg/m3、1.2μg/m3、1.2μg/m3、1.2μg/m3,实验室内相对标准偏差为2.3%～6.6%、2.7%～6.3%、1.8%～6.7%、4.1%～10.5%、3.9%～9.9%、3.8%～7.5%。所建立的测定方法满足对页岩气中苯系物的痕量鉴定。     

环境空气监测用氮气中多组分醛酮气体标准物质的研制

介绍了氮气中13组分醛酮气体标准物质的制备方法。气体标准物质的组分为甲醛、乙醛、丙烯醛、正丁醛、戊醛、2-丁酮、丙酮、丁烯醛、甲基丙烯醛、丙醛、己醛、间甲基苯甲醛和苯甲醛,标准值为1μmol/mol。根据组分的不同性质,经研究采用3步称量法来制备13组分醛酮标准气体,建立了气相色谱-质谱联用及选择扫描离子模式的分析方法,对研制的气体标准物质在气瓶中的均匀性和长期稳定性进行了考察。将研制的气体标准物质分别送至中国计量科学研究院(NIM)和中国环境监测总站(CNEMC)进行了对比测试,取得了良好的对比结果。结果表明,1μmol/mol氮气中13组分醛酮气体标准物质具有较好的均匀性和稳定性,其有效期为12个月,取得了国家二级标物证书,标物号GBW(E)083618。     

Stability of Polycyclic Aromatic Hydrocarbons in Frozen Mussel Tissue

The stability of polycyclic aromatic hydrocarbons (PAHs) in frozen mussel tissue (stored at -80 °C and -120 °C was assessed by analyzing samples of SRM 1974 and SRM 1974a, Organics in Mussel Tissue (Mytilus edulis), since the initial certification analyses. Results of analyses of SRM 1974 and SRM 1974a after 10 years and 6 years of storage, respectively, indicate that the PAH concentrations have not changed. Comparison of results from the analyses of frozen versus freeze-dried mussel tissue samples indicate significant losses of the more volatile PAH such as naphthalene and methylnaphthalenes during the freeze-drying process.     

甲醇转化制芳烃气水油三相体系中各类产物的色谱分析

讨论了甲醇转化制芳烃过程中气水油三相产物的气相色谱分析方法,即:用配备TCD检测器的气相色谱在线分析C1~C5的各种烯烃和烷烃及CO,CO2等气相产物,用配备FID检测器的GC-112A气相色谱分析含各种芳烃的油相和含未反应甲醇的水相。油相和水相中各组分含量重复测定的相对标准偏差均<4.0%,两相中总的标样回收率为95.0%~97.6%,满足样品测定的精密度和准确性要求,若三类样品同时分析,完成1次分析仅需要25 min。     

Formation and emission characteristics of VOCs from a coal-fired power plant

On-site measurements of volatile organic compounds (VOCs) in different streams of flue gas were carried out on a real coal-fired power plant using sampling bags and SUMMA canisters to collect gas samples,filters to collect particle samples,Gas chromatography-flame ionization detector/mass spectrometry and gas chromatography-mass spectrometry was the offline analysis method.We found that the total mass concentration of the tested 102 VOC species at the outlet of wet flue gas desulfuration device was (13456 ± 47) μg·m-3,which contained aliphatic hydrocarbons (57.9％),aromatic hydrocarbons(26.8％),halogen-containing species (14.5％),and a small amount of oxygen-containing and nitrogen-containing species.The most abundant species were 1-hexene,n-hexane and 2-methylpentane.The top ten species in terms of mass fraction (with a total mass fraction of 75.3％) were mainly hydrocarbons with a carbon number of 6 or higher and halogenated hydrocarbons with a lower carbon number.The mass concentration of VOC species in the particle phase was significantly lower than that in the gas phase.The change of VOC mass concentrations along the air pollution control devices indicates that con-ventional pollutant control equipment had a limited effect on VOC reduction.Ozone formation potential calculations showed that aromatic hydrocarbons contributed the highest ozone formation (46.4％) due to their relatively high mass concentrations and MIR (maximum increment reactivity) values.     

Liquid phase methanol reforming with water over silica supported Pt–Ru catalysts

The mechanism of the liquid phase methanol reforming reaction over silica supported Pt–Ru catalyst was investigated by kinetic studies, employing a pyrex glass reactor with reflux condensers connected to a closed gas circulation system under ambient pressure. The rate of H₂ formation over Pt–Ru/SiO₂ catalysts was more than 20 times faster than that over Pt/SiO₂ catalysts with high selectivity for CO₂ (72.3%), indicating a marked addition effect of Ru. In the case of HCHO–H₂O reaction over Pt–Ru/SiO₂, the H₂ formation rate was five times larger than that in the CH₃OH–H₂O reaction but selectivity to CO₂ was only 4%. On the contrary, in the HCOOCH₃–H₂O and HCOOH–H₂O reactions, both high activity and selectivity were observed over Pt–Ru/SiO₂. These results clearly indicate that the CO₂ formation does not proceed via HCHO decomposition and following water gas shift reaction. We propose the following pathway for liquid phase methanol reforming reaction over Pt–Ru/SiO₂; a partly dehydrogenated methanol (CH₂OH^*) is the initial reaction intermediate, from which H₂ and CO₂ are formed through HCOOCH₃ and HCOOH as the successive reaction intermediates.     

液相法甲醇合成过程中机械搅拌反应器的模拟

本文对C301及C302两种不同催化剂条件下机械搅拌反应器内液相法甲醇过程进行了模拟,模拟中节气液之间的传质过程及催化剂气固相本征反应动力学,主要模拟条件：温度483K－528K,压力2．0MPa-6．0MPa,原料气中CO浓度0．06－0．45。模拟结果表明,在C301与C302催化剂条件,隆成总体速率的模拟计算与实测值相吻合,平均偏差分别为7．98％和11．92％,可以认为,气固相本征动力学模型应用于液相甲醇合成过程的工程设计与过程分析是适用和可靠的。     

液相色谱-串联质谱法测定水性涂料中5种异噻唑啉酮生物杀伤剂

建立并优化了水性涂料中 5种异噻唑啉酮生物杀伤剂的检测方法。采用 Optimizer优化软件优化了子离子、碎裂电压和碰撞能量等参数。考察了流动相中甲酸和乙酸铵的含量、流动相梯度洗脱程序、毛细管电压、干燥气流速、雾化器压力、加速电压、干燥气温度等参数对质谱响应的影响。样品用体积分数为 50％的甲醇水溶液或甲醇于容量瓶中经稀释、搅拌和超声提取,提取液经离心分离、过滤膜后,用液相色谱 -串联质谱检测。实验结果表明：在稀释最低 98倍的浓度范围内, 5种异噻唑啉酮的标准曲线线性关系良好,方法的检出限为 0. 001 3~0. 42 mg/kg。空白样品加标回收率在 86. 73％~93. 60％之间,相对标准偏差为 2. 3%~5. 8%。     

Certification of a Diesel Particulate Related Standard Reference Material (SRM 1975) for PAHs

Standard Reference Materials (SRMs) are Certified Reference Materials issued by the National Institute of Standards and Technology (NIST). Three of these materials, SRMs 1975 (Diesel Particulate Extract), 2975 (Diesel Particulate Matter, Industrial Forklift), and 1650 (Diesel Particulate Matter) are diesel particulate-related materials that are well characterized for PAH isomer distributions. SRM 1975 is a methylene chloride extract of industrial forklift diesel particulate matter and it was developed originally in response to the needs of the bioassay community for a natural environmental extract. Thirty-nine PAHs (or combinations of PAHs) were determined in SRM 1975 using various combinations of four different methods of analysis. SRM 1975 will be issued with certified concentrations for eight PAHs. In addition, reference concentrations will be provided for additional PAHs, including many alkyl substituted isomers such as methylphenanthrenes, methylpyrenes, and methylfluoranthenes. Reference values for the mutagenic activity of the extract will also be provided. The approach and results for the certification of PAH concentrations in SRM 1975 are described in this paper.     

不锈钢丝SPME-HPLC联用测定水样中的芳香烃

在修饰过的不锈钢丝表面涂覆(苯乙烯-二乙烯基苯)高内相乳液,制作了不锈钢丝固相微萃取(SPME)萃取头,与高效液相色谱(HPLC)联用测定了环境水样中的芳香烃。系统考察了萃取时间及解吸时间等实验条件对萃取效率的影响,建立了测定环境水样中芳香烃的SPME-HPLC方法。实验结果表明,方法的柱内(n=6)和柱间(n=3)精密度(RSD)分别小于6.5%和8.6%,实际样品的加标回收率在84.4%~95.4%之间;3种芳香烃化合物的线性范围为5~200μg/L,线性相关系数r>0.9960,检出限在0.09~0.20μg/L之间。该方法快速、灵敏、简便,适用于快速分析环境水样中的芳香烃。     

浆态床甲醇合成反应过程数学模拟

在固定床等温积分反应器中回归了LP201催化剂上的甲醇合成反应动力学参数,在液固拟均相、全混流、气相流动形式分别为全混流、平推流的基础上建立了浆态床搅拌反应器中甲醇合成反应的数学模型. 模拟结果显示,根据所得动力学参数,计算结果与实验结果吻合良好;气相甲醇合成过程中气相流动形式明显影响反应效率;在液相甲醇合成过程中,气相的流动形式对反应影响不大;气液传质阻力对反应有较显著的影响,必须与反应过程同时加以考虑.     

SPE-GC/MS法快速检测水体中多组分内分泌干扰物

采用固相萃取-气相色谱/质谱法(SPE-GC/MS)研究了温州8个水体中邻苯二甲酸二甲酯、西玛津、莠去津、甲草胺、邻苯二甲酸二丁酯、双酚A、邻苯二甲酸二(2-乙基己基)酯七种内分泌干扰物的残留。水样用C18柱固相萃取进行富集、3mL10%的甲醇水溶液淋洗、10mL丙酮洗脱;并采用GC-MS法对七种内分泌干扰素进行分析。本实验建立的方法定性定量准确、可靠,适用于水体中多组分内分泌干扰物的快速检测,在所有测定的水样中,邻苯二甲酸二丁酯、双酚A、邻苯二甲酸二(2-乙基己基)酯是主要残留物,最高残留邻苯二甲酸二丁酯、双酚A、邻苯二甲酸二(2-乙基己基)酯分别为0.82、3.16、1.50ng/L。