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1.
水中松节油气相色谱的测定方法研究 总被引:4,自引:3,他引:1
研究建立了气相色谱和气-质联用法测定水中松节油的方法.用二氯甲烷萃取水样中的松节油,萃取后直接进行色谱分离分析,松节油的主要成分能有效分离,水中松节油的最低检测浓度气相色谱法为0.01mg/L,气-质联用法可达0.001mg/L;准确度好,两种测定方法的样品添加回收率在90.3%~115%之间;平行6次进行精密度试验,两种分析方法的相对标准差低于5.9%.结果表明,气相色谱法简便、快速、准确、重现性好,适合地表水中松节油的测定.选择离子气-质联用法可排除干扰,定量、定性更加准确可靠,适合复杂水样的分析. 相似文献
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选用配备了2种不同检测器(电导检测器和直流安培检测器)的离子色谱仪对稀释后过0.22μm滤膜的水样进行分析。配备有直流安培检测器的离子色谱仪测定水中碘化物的方法在0.100~20.0μg/L范围内线性关系良好,相关系数(r)=0.9999,方法检出限为0.030μg/L,测定下限为0.120μg/L,样品加标回收率为95.0%~104%,相对标准偏差为1.06%~1.64%;配备有电导检测器的离子色谱仪测定水中碘化物的方法在20.0~2.00×105μg/L范围内线性关系良好,相关系数(r)=0.9995,方法检出限为2.00μg/L,测定下限为8.00μg/L,样品加标回收率为99.0%~110%,相对标准偏差为0.71%~3.12%。离子色谱-直流安培检测器法测定水中碘化物的方法准确度高、灵敏度高、精密度好,检出限相对较低,适用于测定ρ(碘化物)≤20.0μg/L的清洁水样;离子色谱-电导检测器法主要适用于测定ρ(碘化物)≥20.0μg/L的水样。 相似文献
3.
环境水体中痕量酚类化合物气相色谱-质谱联用测定法研究 总被引:6,自引:2,他引:6
建立了液-液萃取-气相色谱/质谱联用仪测定环境水体中痕量酚类化合物的方法。用乙酸乙酯萃取环境水中的痕量酚类化合物,加入萘-d8作为内标,利用气相色谱-质谱联用仪选择离子监测(SIM)的方式进行检测,内标法定量,定性、定量准确,线性响应良好,回归曲线的相关系数均>0.999,平均回收率在89.4%~104%之间,精密度好,相对标准偏差<7.4%;抗干扰能力强,检测灵敏度高,水样中最低检测浓度可达0.001mg/L,经实际样品测定完全能满足环境水体中痕量酚类化合物监测的要求。 相似文献
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采用固相萃取-高效液相色谱(SPE - HPLC)二极管阵列检测器同时测定水中呋喃丹、甲萘威和阿特拉津,以甲醇-水为流动相,采用梯度洗脱方式,选择220 nm为检测波长,二氯甲烷为洗脱剂.呋喃丹在0.200 mg/L ~5.00 mg/L、甲萘威和阿特拉津在0.020 mg/L~5.00 mg/L范围内线性良好,检出限... 相似文献
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水样经聚四氟乙烯滤头过滤,直接用超高效液相色谱-三重四极杆串联质谱(UPLC-MS/MS)同时测定甲萘威、呋喃丹和阿特拉津。通过试验考察不同材质滤头和各仪器条件对测定的影响,并确定最佳分析条件,使该方法在0.01μg/L~10.0μg/L范围内线性良好。甲萘威、呋喃丹和阿特拉津的方法检出限分别为6.1 ng/L、2.8 ng/L、3.1 ng/L,空白水样的3个质量浓度加标回收率在96.4%~110%之间。该方法用于测定实际水源水及饮用水中的甲萘威、呋喃丹和阿特拉津,结果均未检出,实际水样平均加标回收率为81.4%~97.2%。 相似文献
6.
建立了二氯甲烷提取、高效毛细管柱分离、气相色谱-氮磷检测器测定水中呋喃丹的方法.优化了试验条件,以HP-5和HP-1301双柱定性,方法在0.00 mg/L~1.00 mg/L之间线性良好,检出限为2.0×10-5 mg/L,RSD≤6.5%,加标回收率为93.6%~110%. 相似文献
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离子选择电极法测定水中氟离子影响因素的探讨 总被引:1,自引:0,他引:1
离子选择电极法测定水中氟离子的监测方法,因其操作简单、干扰少、不必进行预处理等优点,广泛应用于环境监测领域。但国家标准检测方法对检测过程条件控制及影响因素等没有明确写明。本文结合实验和文献资料,对检测过程中出现的结果偏差进行了探讨。 相似文献
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An important research area in life sciences is devoted to modeling, prediction, and dynamics of gene-expression patterns.
As clearly understood in these days, this enterprise cannot become satisfactory without acknowledging the role of the environment.
To a representation of past, present, and most likely future states, we also encounter measurement errors and uncertainties.
This paper surveys and improves recent advances in understanding the foundations and interdisciplinary implications of the
newly introduced gene–environment networks, and it integrates the important theme of carbon dioxide emission reduction into
the networks and dynamics. We also introduce some operational and managerial issues of practical working and decision making,
expressed in terms of sliding windows, quadrants (modules) of parametric effects, and navigating (controlling) between such effects and directing them. Given data from DNA microarray experiments and environmental records, we extract
nonlinear ordinary differential equations that contain parameters that have to be determined. For this, we employ modern (Chebychevian)
approximation and (generalized semi-infinite) optimization. After this is provided, time- discretized dynamical systems are
studied. A combinatorial algorithm with polyhedra sequences allows to detect the region of parametric stability. Finally,
we analyze the topological landscape of gene–environment networks with its structural (in)stability. By embedding as a module
and investigating CO2 emission control and figuring out game theoretical aspects, we conclude. This pioneering work is theoretically elaborated,
practically devoted to health care, medicine, education, living conditions, and environmental protection, and it invites the
readers to future research.
相似文献
12.
Ellis A. M. Franssen Brigit A. M. Staatsen Erik Lebret 《Environmental Impact Assessment Review》2002,22(6)
In this article a comprehensive approach for the evaluation of possible health effects in an environmental impact assessment (EIA) is described, illustrated with the example of Amsterdam Airport Schiphol. Unlike many EIAs, we estimated quantitatively the impact of aircraft-related pollution in terms of the number of affected people for aircraft noise annoyance, odour annoyance and hypertension. In addition, an analysis of health registry data on cardiovascular and respiratory diseases and a short survey on annoyance and risk perception were carried out. The scope of a health impact assessment depends on the situation, available knowledge and data, concern in the population about the impact and the number of people concerned. It is important to pay attention to the perception of risks and concerns from all parties involved. Moreover, the results demonstrate that far more people outside the area for which standards apply were affected than inside. 相似文献
13.
Clifford A. Hui John Y. Takekawa Sarah E. Warnock 《Environmental monitoring and assessment》2001,71(2):107-121
The San Francisco Bay estuary isused by over one million shorebirds during springmigration and is home to several hundred thousandduring the winter. Most shorebird use occurs in thesouthern reach of the estuary (South Bay). Thereduced water circulation and discharge fromindustrial sources in the South Bay are responsiblefor the highest levels of some trace elements in theestuary. Wintering shorebirds have been found to havestrong site fidelity to areas as small as a fewkilometers in the South Bay, which may increase theirexposure to contaminants near local point sources. Inaddition, different shorebird species foraging at thesame site have been shown to have differentcontaminant burdens. Thus, our objectives were totest whether contaminant burdens differed by species,or whether contaminant burdens differed in shorebirdscollected at adjacent sites. We examined thecontaminant profiles of two species of shorebirds,long-billed dowitchers (Limnodromus scolopaceus)and western sandpipers (Calidris mauri) thatforage together at two sites, Hayward and Newark,separated by 8 km in the South Bay. We usedmultivariate analysis of variance tests to compare thecomposition of 14 elemental analytes in their livertissues and estimated their molar ratios of Hg and Se. Composite samples were used for contaminant analysesbecause of the small body size of the shorebirds. Seven elemental analytes (Ag, Ba, Be, Cr, Ni, Pb, V)were below detection limits in a majority of thesamples so statistical analyses were precluded. Inthe measurable analytes (As, Cd, Cu, Hg, Mn, Se, Zn),we found no significant intra-site differences ofcontaminant profiles for the two species. We pooledthe samples to examine inter-site differences andfound significant differences in contaminant profilesbetween shorebirds at the neighboring sites (P = 0.03). Shorebirds at Newark had higher (P < 0.05) concentrations of As, Cd, and Se than those at Hayward. Dowitchers at Newark had concentrations of Hg and Se which were highly correlated (P < 0.003) in a mean molar ratio of 1:19, similar tothat reported in other birds. In the larger dowitcherspecies, we also examined exposure to 20organochlorine compounds. Organic analyses showedthat the dowitchers had been exposed to DDE, PCBs,dieldrin and trans-nonachlor, but with no significantdifferences in concentrations between Hayward andNewark (P > 0.05). 相似文献
14.
土壤和底泥中砷、铬、锰测定的前处理技术 总被引:6,自引:0,他引:6
试验了土壤和底泥中砷的前处理技术,其目的是能对土壤、底泥中砷、铬、锰在一次前处理中制备成试液,比色法分析。试验表明,用H2SO4-H3PO4-H2O2进行前处理是可行的。方法简单、挥发酸雾少,用标准参考物质检验证明,分解完全,数据准确,有粒较好一致性。 相似文献
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Material Disposal Area G is the primary low-levelradioactive waste disposal site at Los Alamos NationalLaboratory, New Mexico, and is adjacent to Pueblo of SanIldefonso lands. Pueblo residents and Los Alamos scientists areconcerned about radiological doses resulting from uptake of AreaG radionuclides by mule deer (Odocoileus hemionus) andRocky Mountain elk (Cervus elaphus), then consumption ofdeer and elk meat by humans. Tissue samples were collected fromdeer and elk accidentally killed near Area G and were analyzedfor 3H, 90Sr, total U, 238Pu, 239, 240Pu,241Am, and 137Cs. These data were used to estimatehuman doses based on meat consumption of 23 kg y-1. Humandoses were also modeled using RESRAD, and dose rates to deer andelk were estimated with a screening model. Dose estimates tohumans from tissue consumption were 2.9 × 10-3 mSv y-1and 1.6 × 10-3 mSv y-1 from deer and elk, respectively,and RESRAD dose estimates were of the same order of magnitude. Estimated dose rates to deer and elk were 2.1 × 10-4 mGyd-1 and 4.7 × 10-4 mGy d-1, respectively. Allestimated doses were significantly less than established exposurelimits or guidelines. 相似文献
16.
This paper presents the chemical speciation and retention behavior of chromium (Cr), nickel (Ni), and cadmium (Cd) prior to
and after the electrokinetic remediation in glacial till soil. The speciation of the metals was predicted using the chemical
speciation program MINEQL+. The simulations were performed for single-contaminant with only Cr(VI) or Ni, and multi-contaminants consisting of: (1)
Cr(VI), Ni, and Cd; (2) Cr(III), Ni and Cd; (3) Cr(VI), Cr(III), Ni and Cd; (4) Cr(VI), Ni, and Cd with reducing agents; and
(5) Cr(III), Ni, and Cd with oxidizing agent (Mn). The results showed that the speciation and distribution of cationic metals
[Ni, Cd, and Cr(III)] in glacial till soil remain unaffected or slightly affected during electrokinetics. This is attributed
to the high pH buffering capacity of the glacial till, leading the metals to precipitate in the soil prior to and after electrokinetics.
This study showed that during electrokinetics, Cr(VI) existed as anionic complex and migrated towards the anode and the migration
is maximum in case of a single-contaminant system. The study also showed that near the anode in the absence of any reducing
and oxidizing agent, Cr(VI) mostly adsorbed, and some of Cr(VI) reduced to Cr(III) and migrated towards the cathode and finally
precipitated due to high pH conditions. Ni and Cd remain adsorbed or precipitated due to the high pH conditions throughout
the soil. Among the reducing agents, the sulfide had significant effect on the migration of metals compared to ferrous ions.
While in the presence of oxidizing agent (Mn), no noticeable Cr(VI) was found in the soil sample indicating the reduction
of Cr(VI) to Cr(III) and the predominance of reducing conditions due to the presence of naturally occurring iron in the glacial
till soil. Overall, this study provides a reasonable explanation of the speciation and distribution of chromium, nickel and
cadmium during the electrokinetic remediation of glacial till soil. 相似文献
17.
Besser JM Brumbaugh WG May TW Schmitt CJ 《Environmental monitoring and assessment》2007,129(1-3):227-241
We evaluated exposure of aquatic biota to lead (Pb), zinc (Zn), and cadmium (Cd) in streams draining a Pb-mining district
in southeast Missouri. Samples of plant biomass (detritus, periphyton, and filamentous algae), invertebrates (snails, crayfish,
and riffle benthos), and two taxa of fish were collected from seven sites closest to mining areas (mining sites), four sites
further downstream from mining (downstream sites), and eight reference sites in fall 2001. Samples of plant biomass from mining
sites had highest metal concentrations, with means 10- to 60-times greater than those for reference sites. Mean metal concentrations
in over 90% of samples of plant biomass from mining sites were significantly greater than those from reference sites. Mean
concentrations of Pb, Zn, and Cd in most invertebrate samples from mining sites, and mean Pb concentrations in most fish samples
from mining sites, were also significantly greater than those from reference sites. Concentrations of all three metals were
lower in samples from downstream sites, but several samples of plant biomass from downstream sites had metal concentrations
significantly greater than those from reference sites. Analysis of supplemental samples collected in the fall of 2002, a year
of above-average stream discharge, had lower Pb concentrations and higher Cd concentrations than samples collected in 2001,
near the end of a multi-year drought. Concentrations of Pb measured in fish and invertebrates collected from mining sites
during 2001 and 2002 were similar to those measured at nearby sites in the 1970s, during the early years of mining in the
Viburnum Trend. Results of this study demonstrate that long-term Pb mining activity in southeast Missouri has resulted in
significantly elevated concentrations of Pb, Cd, and Zn in biota of receiving streams, compared to biota of similar streams
without direct influence of mining. Our results also demonstrate that metal exposure in the study area differed significantly
among sample types, habitats, and years, and that these factors should be carefully considered in the design of biomonitoring
studies. 相似文献
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The present study demonstrates comparison of Cr accumulatingpotential by the plants of Najas indica Cham. (submerged),Vallisneria spiralis L. (rooted submerged) and Alternanthera sessilis R. Br. (rooted emergent) under repeatedmetal exposure and its effect on chlorophyll and protein concentrations. These plants were treated with different concentrations of Cr under repeated exposure in controlled laboratory conditions to assess the maximum metal accumulationpotential. The plants of V. spiralis accumulated significantly high amount of Cr under laboratory conditions incomparison to N. indica and A. sessilis. The maximumaccumulation of 1378, 458 and 201 g g-1 dw Cr was found in the leaves of V. spiralis, N. indica and A. sessilis, respectively at 8 mg L-1 after 9 day of Cr exposure. These plants have shown a decrease in chlorophyll andprotein concentrations with increase in Cr concentrations. In view of high accumulation of Cr in V. spiralis, the plantswere treated with different concentrations of tannery effluent collected from Common Effluent Treatment Plant, Unnao (UP). Theplants of V. spiralis treated with 100% tannery wastewatershowed the maximum accumulation (57.5 g g-1 dw) of Cr in the roots after 10 days of exposure. The plants were foundeffective in removing Cr from solution and tannery effluent. 相似文献
20.
Ravindra K Wauters E Tyagi SK Mor S Van Grieken R 《Environmental monitoring and assessment》2006,115(1-3):405-417
Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM10, CO, SO2 and NOx) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO2 and CO concentrations, while the NOx level was increased in comparison to those before the implementation of CNG. Further, SPM, PM10, and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi. 相似文献