离子色谱法测定碳酸锶产品中的氯杂质

讨论了在单柱离子色谱仪上用ＴＳＫｇｅｌＩＣ－Ａｎｉｏｎ－ＳＥ柱为分离柱，１ｍｍｏｌ／Ｌ邻苯二到（ＰＨ５．４）作流动相，以电导检测器检测，测定沸水提取碳酸锶产品中的杂质氯的方法。该法简便、快速、准确、无干扰，在测定范围内有良好的线性。最小检出量为０．１μｇ，ＩＣ法与比色法的测定结果基本一致，ＣＩ＾－的含量为０．１６６％，相对标准偏差为２．８％，回收率为９７．９％～１００％。     

气相色谱法测定水中的毒鼠强

用火焰光度气相色谱法测定水中毒鼠强的含量，按正交试验法选择最佳操作条件，试验测得回收率９６．５％－１０５．４％，相对标准偏差４．９％－７．２％，线性范围２４－１２９ｍｇ，最低检出量１２ｎｇ，测定结果令人满意。     

微分脉冲伏安法测定降水中锌、镉、铅和铜

以量浓度为0．01mol/L的高氯酸为支持电解质，采用微分脉冲阳极溶出伏安法同时测定降水中的痕量Zn^2 、Cd^2 、Pb^2 和Cu^2 ．6次测定的相对标准偏差均小于5％，降水样品镉未检出。锌、铅、铜的加标回收率分别为91．5％－110．0％、91．5％－104．0％和91．0％－106．0％。该方法应用于降水中Zn、Cd、Pb、Cu痕量元素的分析，具有方法简便、快速、准确度高等特点。     

气相色谱法测定空气中三氯乙烯和四氯乙烯

应用气相色谱法以５％ＰＥＧ－６０００为固定液、６２０１为担体填充柱分离，电子捕获检测器检测，直接进样测定环境空气中三氯乙烯和四氯乙烯。对０．０２９ｍｇ／ｍ＾３四氯乙烯标准样作重复５次测定，其相对标准差分别为５．７％和１．５％，并在实际样品中进行加标回收试验，回收率三氯乙烯在９０％～１１０％、四氯乙烯在９４％～１０８％之间。检测限分别为０．００６ｍｇ／ｍ＾３和０．０００５ｍｇ／ｍ＾３，完全能满足环境     

固上顶空气相色谱法测定樟脑和萘

本文对固上顶空气相色谱法的理论和测定条件进行了研究。用于樟脑和萘的测定，最小检出量达１０－９ｇ，回收率为９６．０～１０１．３％．本法基体干扰小，操作简便．     

石墨炉原子吸收法测定废水中锑

以钯作基改进剂建立了测定废水中锑的石墨炉原子吸收光谱分析法。方法线性范围为０ｍｇ／Ｌ－１０ｍｇ／Ｌ，检测限为０．０２ｍｇ／Ｌ。相对标准差为３％，回收率为９６．７％－１０１．３％，结果令人满意。     

应用化学放大原理测定水中的挥发酚

测定水中高含量酚一般用溴化容量法，但在含量相对偏低时，由于消耗硫化硫酸钠的量少会使分析误差增大，笔者应用化学放大原理，可使测定灵敏度提高6倍，有效地降低了测定误差，其测定线性范围为50－200ug，使500ug以上的酚变异系数不于1．5％，500ug以下的酚变异系数不超过2．2％。     

高锰酸钾——硫酸——过硫酸钾消化冷原子荧光法测定总悬浮颗粒物中…

测定环境大气悬浮颗粒物中痕量汞，用４种消化液进行对比实验，其中高锰酸钾－硫硫－过硫酸钾混合液消化效果较好，用冷原子荧光测定操作简便，检测下限为０．０５μｇ／Ｌ，重复测定９个实际样品，相对标准偏差为１１．６％，变异系数为１０．４％，添加汞标准回收率为１０２％。     

气相色谱法测定鱼组织中的久效磷

采用气相色谱法氮磷检测器测定鱼肉和内脏中的久效磷含量。鱼肉或内脏匀浆后，用正己烷洗涤，二氯甲烷提了，以内标法定量分析，方法简单，灵敏，准确。当取鱼组织0．5g时，方法检测限为0．002mg/kg，加标回收率为72．6％－83．3％，相对标准差在3．3％－7．0％之间。     

大气飘尘中碲的测定－原子荧光法

本法使用美国进口的大流量采样器采样，用国产的玻璃纤维滤膜作滤材，以硝酸、高氯酸分解，硼氢化钾还原－无色散原子荧光法对碲进行测定。本法在采样体积３６０ｍ３，最低检出浓度５．８×１０－５μｇ／ｍ３，精密度５．７－９．６％，回收率８７．０－１１０．０％，结果令人满意，适于大气飘尘中碲的测定     

Simulating the Sorptive Removal of Dissolved Copper by Biocarrier Beads

Biocarrier beads containing the dead biomass of Bacillus drentensis immobilized in polymer polysulfone were synthesized in order to remove heavy metals from wastewater. A series of batch experiments were carried out to identify the sorption mechanisms and the theoretical nature of the underlying processes. A mathematical model was developed to simulate the fate and transport of copper ions in a saturated fixed bed packed with biocarrier beads. Mass balance equations were established to represent the migration and distribution of metal ions in the biocarrier beads and the surrounding bulk liquid. Numerical experiments were performed using the proposed model for quantitative analysis of the temporal changes in the distribution of copper ions in and around the biocarrier beads in a fixed bed. The simulation results show that the biosorption of heavy metals by the biocarrier beads depends largely on surface adsorption. A sensitivity analysis was carried out on the major design parameters in a fixed bed. The effects of bed height, flow velocity, and influent concentration were examined by assessing a simulated breakthrough curve. The breakthrough time occurs earlier for a decreasing bed height and increasing flow velocity and influent Cu(II) concentration, whereas the slope at 50 % breakthrough becomes steeper as the flow velocity increases and the influent concentration decreases. The simulation results show that the proposed mathematical model can provide a quantitative analysis of the distribution of metal adsorbate in and around porous particulate adsorbents in a fixed bed and that it can be used as an effective predictive tool.     

定电位电解法测定烟气中氮氧化物的不确定度评定——以湿法脱硫除尘电厂为例

以某湿法脱硫除尘电厂为例,对定电位电解法测定烟气中氮氧化物的不确定度进行评定。分析认为,测量结果的不确定度可能来自于仪器的校准过程、重复性测量过程和其他气体或杂质的干扰,通过将定电位电解法和紫外分光光度法进行对比分析,确定其他气体或杂质的干扰在本分析过程中造成的不确定度可以忽略。最终计算得出,此次使用3012H型自动烟尘测试仪测量氮氧化物的相对扩展不确定度为±6.57%,其中B类不确定度分量的贡献较大,在分析过程中应加强仪器的维护与保养。     

Pesticide vapours in confined atmospheres. Determination of dichlorvos by SPME-GC-MS at the microg m(-3) level

A method based on SPME is described for assessing the gaseous dichlorvos concentration in confined atmospheres like a greenhouse after a pesticide application. Sampling was made by using SPME with PDMS fibres immersed into a 250 mL sampling flask into which air samples were dynamically pumped from the analysed atmosphere. Sampling duration was 40 min and samples were then analysed by GC-MS. Calibration was performed from a vapour saturated air sample and gas phase diluted samples, and this procedure afforded a curve with a regression coefficient (R2) higher than 0.98. The repeatability of these measurements was observed with an RSD of 2.5%. This analysis procedure was then applied for the determination of gaseous dichlorvos concentrations versus time, in the atmosphere of an experimental 8 m2 and 20 m3 greenhouse. The pesticide was sprayed according to real cultivation conditions and measurements were made from 2 up to 74 h after application affording observed concentrations in the range of decades and hundreds of microg m(-3) (corresponding limits of detection and quantification were found at the level of a few microg m(-3)).     

恶臭源厂界空气中恶臭物质监测技术要点及结果分析探讨——以西安市某大型垃圾填埋场为例

建立了水杨酸-次氯酸钠法分析氨的标准曲线,通过对西安市某垃圾填埋场的实地监测,探索了恶臭气体中氨气的分析方法。分析了臭气、氨气、硫化氢之间的浓度相关性,利用本次监测数据,找出了针对该垃圾处理场的高浓度氨气样品初步分析方案。恶臭产生的主要点位为垃圾场渗滤液污水处理站及下游区域,垃圾场臭气呈现出由点源污染(作业面)到面源污染扩散的态势。     

Source apportionment in oil spill remediation

A pipe rupture during unloading led to a spillage of 350-700 tonnes of Ca?o Limon, a light sweet crude oil, into San Vicente Bay in 2007. Initial clean-up methods removed the majority of the oil from the sandy beaches although some oil remained on the rocky shores. It was necessary for the responsible party to clean the spilled oil even though at this location there were already crude oil hydrocarbons from previous industrial activity. A biosolvent based on vegetable oil derivatives was used to solubilise the remaining oil and a statistical approach to source apportionment was used to determine the efficacy of the cleaning. Sediment and contaminated rock samples were taken prior to cleaning and again at the same locations two days after application of the biosolvent. The oil was extracted using a modified USEPA Method 3550B. The alkanes were quantified together with oil biomarkers on a GC-MS. The contribution that Ca?o Limon made to the total oil hydrocarbons was calculated from a Partial Least Squares (PLS) analysis using Ca?o Limon crude oil as the source. By the time the biosolvent was applied, there had already been some attenuation of the oil with all alkanes 相似文献   

趸船式水质自动监测站建站模式的技术可行性分析

分析大胜关水质自动监测站建成运行后2015-2018年每月实际水样比对数据,并与同期建设固定式水站水样比对结果比较,探讨趸船式水站的技术可行性。结果表明:趸船式水站自动监测的pH值、溶解氧、电导率、氨氮指标与实验室数据有较好一致性,相关性均>0.7,且显著性概率<0.01,存在非常显著的相关关系,pH值、电导率、高锰酸盐指数3个指标的实际水样比对合格率均超过80%,其中高锰酸盐指数和氨氮指标的误差范围与固定式水站监测结果的误差范围相当。     

Stochastic landslide vulnerability modeling in space and time in a part of the northern Himalayas, India

Little is known about the quantitative vulnerability analysis to landslides as not many attempts have been made to assess it comprehensively. This study assesses the spatio-temporal vulnerability of elements at risk to landslides in a stochastic framework. The study includes buildings, persons inside buildings, and traffic as elements at risk to landslides. Building vulnerability is the expected damage and depends on the position of a building with respect to the landslide hazard at a given time. Population and vehicle vulnerability are the expected death toll in a building and vehicle damage in space and time respectively. The study was carried out in a road corridor in the Indian Himalayas that is highly susceptible to landslides. Results showed that 26% of the buildings fall in the high and very high vulnerability categories. Population vulnerability inside buildings showed a value >0.75 during 0800 to 1000 hours and 1600 to 1800 hours in more buildings that other times of the day. It was also observed in the study region that the vulnerability of vehicle is above 0.6 in half of the road stretches during 0800 hours to 1000 hours and 1600 to 1800 hours due to high traffic density on the road section. From this study, we conclude that the vulnerability of an element at risk to landslide is a space and time event, and can be quantified using stochastic modeling. Therefore, the stochastic vulnerability modeling forms the basis for a quantitative landslide risk analysis and assessment.     

The influence of water vapour on the determination of glutaraldehyde vapour concentrations using an electrochemical fuel cell sensor

The effects of relative humidity (40-90% RH) and varying glutaraldehyde vapour concentrations (< 0.1 ppm) on the response of an electrochemical fuel cell sensor have been investigated over time (0-400 s). These studies have identified changes in the response of the fuel cell with time after sampling. In particular, it has been found that the maximum cell output for water vapour occurs ca. 10 s after sampling whilst the response to glutaraldehyde occurs much later (> 100 s). For mixtures containing different ratios of water and glutaraldehyde vapours, the time taken to reach maximum fuel cell response varies between 10 and 100 s, depending on the ratio of the two vapours. For instance, glutaraldehyde vapour containing higher % RH has been found to result in shorter times to reach maximum fuel cell response. A comparison was made between measuring glutaraldehyde vapour concentrations in the presence of water vapour at the maximum fuel cell response and also at a fixed interval (240 s) after sampling. Such a comparison resulted in a reduction in the standard error from 36% to 5% for a glutaraldehyde vapour sample (0.023 ppm) measured at different values of relative humidity (40 to 80%). Examination of the effect of the sample volume (30-60 ml) on the response of the fuel cell shows, as expected, an approximate doubling of the fuel cell response. Optimisation of the fuel cell measurement parameters to measure a 60 ml sample leads to a lowering of the limit of detection from 0.083 ppm (for data taken at the maximum cell response) to 0.017 ppm for data measured 240 s after sampling. In the light of recent reductions in the legal limits for exposure to glutaraldehyde, this has important implications for the measurement of glutaraldehyde vapour in the workplace.     

Landsat and limnologically derived water quality data: A perspective

Fixed station sampling is the conventional method used to obtain data on the median water quality of reservoirs. A major source of uncertainty associated with this technique is that water quality at the fixed stations may not be representative of the ambient water quality in the reservoir at the time of sampling. This problem is particularly relevant for water quality variables such as chlorophyll, which have a markedly patchy spatial distribution. The use of Landsat reflectance data to estimate median chlorophyll concentrations in Roodeplaat Dam was investigated. A linear polynomial regression model for estimating chlorophyll concentrations from Landsat reflectance data, was firstly calibrated with chlorophyll concentration data obtained by sampling seven fixed stations on the reservoir at the time of the satellite overflight to produce an individual calibration. Secondly, the model was calibrated with a pooled set of sampled data obtained from five separate overflights, to obtain a generalised calibration.It was found that median chlorophyll concentrations determined from Landsat-derived data were similar to median chlorophyll concentrations estimated from fixed station data. However, the range of chlorophyll concentrations in the reservoir estimated from Landsat data was considerably larger than that estimated from fixed station data. Landsat derived estimates of chlorophyll concentrations have the added advantage of providing information on the spatial distribution of chlorophyll in the reservoir.     

A comparison of sampling and analysis methods for low-ppbC levels of volatile organic compounds in ambient air

A carefully designed study was conducted during the summer of 1998 to collect samples of ambient air by canisters and compare the analysis results to direct sorbent preconcentration results taken at the time of sample collection. Thirty-two 1 h sample sets were taken, each composed of a "near-real-time" sample analyzed by an autoGC-MS XonTech 930/Varian Saturn 2000 system, and Summa and Silco canisters. Hourly total non-methane organic carbon (TNMOC), ozone, and meteorological measurements were also made. Each canister was analyzed on the autoGC-MS system for a target list of 108 volatile organic compounds (VOCs) and on a manual cryosampling GC-FID system. Comparisons were made between the collection and analysis methods. Because of the low sample loading (150-250 ppbC TNMOC), these comparisons were a stringent test of sample collection and analysis capabilities. The following specific conclusions may be drawn from this study. Reasonable precision (within 15% mean difference of duplicate analyses from the same canister) can be obtained for analyses of target VOCs at low-ppbC concentrations. Relative accuracy between the GC-MS and GC-FID analysis methods is excellent, as demonstrated by comparisons of analyses of the same canisters, if measurements are sufficiently above the detection limits. This is especially significant as the GC-MS and GC-FID were independently calibrated. While statistically significant differences may be observed between the results from canister and near-real-time samples, the differences were generally small and there were clear correlations between the canister results and the near-real-time results. Canister cleanliness limits detection below the EPA Method TO-14 acceptance standard of 0.2 ppbv (0.2-2 ppbC for target analytes).