液液萃取-HPLC-ICPMS联用技术测定水体中甲基汞

建立了二氯甲烷萃取,半胱氨酸-乙酸铵溶液反萃取,液相色谱-电感耦合等离子体质谱法测定水中甲基汞的方法。取样量为1 L时,方法检出限为0.1 ng/L,相对标准偏差为6.6%~13%,地表水、生活污水和工业废水3种实际水样的加标回收率分别为45.6%~70.5%、37.0%~65.6%、18.4%~61.8%。与5种甲基汞测定方法的前处理过程、分析仪器和检出限进行了比较,并讨论了无机汞的干扰情况及如何降低体系空白和消除无机汞干扰的质量控制手段。     

废水总氰化物测定干扰的消除

为解决测定受有机物污染的城镇污水原水中氰化物含量过程中出现的总氰化物未检出,进出水总氰化物浓度倒大等问题,采取增加石油醚(90~120℃)萃取或银盐沉淀预处理的步骤,实现对干扰的消除,方法相对标准偏差在4.8%~26.5%之间,加标回收率在84%~90%之间。     

固相微萃取-GC/MS法测定水中18种酚类化合物

采用固相微萃取-气相色谱/质谱联用法测定水中18种酚类化合物,优化了溶液pH值、萃取时间、萃取温度、搅拌速率等萃取条件。方法在0.110 mg/L~1.61 mg/L范围内线性良好,18种酚类化合物的检出限为0.001 mg/L~0.015 mg/L(SIM)和0.003 mg/L~0.035 mg/L(SCAN),污水样品加标回收率为88.4%~97.4%。     

固相萃取-液相色谱-串联质谱法测定水中5种雌激素

建立了固相萃取-液相色谱-串联质谱组合联用技术同时测定地表水、饮用水和污水处理厂出厂水中的5种雌激素(17β-雌二醇、雌三醇、雌酮、17α-炔雌醇、己烯雌酚)的方法。水样经过全自动固相萃取仪富集,以OASIS HLB柱为萃取柱,甲醇为洗脱剂,用液相色谱-串联四极杆质谱联用仪分析定量。分别在0.5~8、5~80μg/L范围内线性良好,相关系数为0.995~0.998。17β-雌二醇、雌三醇、17α-炔雌醇的检出限均为5μg/L,雌酮与己烯雌酚的检出限为0.5μg/L。5种雌激素的纯水加标回收率为63.6%~120.2%,地表水加标回收率为59.8%~91.5%,自来水加标回收率为55.3%~92.1%,精密度为3.7%~10.7%,该方法简单、可靠,可用于水中雌激素类污染物的同时测定。     

磁性分散固相萃取气相色谱法测定地表水中有机磷化合物

应用磁性分散固相萃取技术对环境水体中有机磷化合物进行萃取测定,并对萃取剂的用量、萃取时间、解吸溶剂、盐度等实验影响因素进行了优化。在优化条件下,有机磷的回收率为80.1%~93.1%,相对标准偏差为4.6%~5.9%,检出限为0.000 2~0.000 4 mg/L。与传统的液液萃取及固相萃取相比,该磁性分散固相萃取方法操作更为简单、迅速,有机溶剂消耗量很少,方法环保。能很好的满足环境水体中有机磷化合物的测定。     

在线蒸馏-无人值守连续流动分析法测定污水中氨氮

采用在线蒸馏-无人值守连续流动分析法对污水中氨氮进行检测,方法在0.00~10.0 mg/L范围内线性良好,检出限为0.014 mg/L,实际样品测定的相对标准偏差为1.24%~4.15%,加标回收率为93.0%~108%,精密度和准确度均能满足污水中氨氮的测定要求。     

小体积液液萃取气相色谱法测定地表水中硝基苯类

建立了一种小体积液液萃取气相色谱法快速测定地表水中硝基苯类化合物的分析方法。方法具有适用性广、溶剂用量少和操作简便等特点。当萃取剂甲苯用量为1.5 ml时,萃取富集效率可达191~332倍,回收率为90.7%~102%,相对标准偏差为2.9%~5.1%,检出限为0.000 3~0.005 mg/L。     

分散液液微萃取-气相色谱/质谱联用法测定饮用水源水中的四乙基铅

采用分散液液微萃取与气相色谱/质谱法联用技术建立了测定水样中四乙基铅的方法。考察了影响分散液液微萃取的因素,包括萃取溶剂、分散剂、萃取次数、萃取时间和盐效应等。在最佳条件下,四乙基铅的富集倍数为330倍,检出限为0.01μg/L(S/N=3),线性范围为0.10~10.0μg/L,线性相关系数为0. 9992。测定饮用水源水中的四乙基铅,加标回收率为87.7%~105%,相对标准偏差为4.8%~7.3%(n=3)。     

液-液小体积萃取GC-MS方法快速测定地表水中的氯苯类化合物

建立了一种液-液小体积萃取GC-MS快速测定地表水中氯苯类化合物的分析方法。该方法具有操作简单快速、适用性广和试剂用量很少等特点。当萃取试剂用量为2ml时(约为一般常规液-液萃取用量的数十分之一),萃取富集效率可达300~500倍,回收率为93%~98%,相对标准偏差为4%~8%,检出限为0.1~0.3μg/L。     

分散液液微萃取-气相色谱法测定地表水中松节油

采用分散液液微萃取-气相色谱法测定地表水中松节油,通过试验优化萃取剂、分散剂的种类和用量、盐度等影响萃取效率的条件,使该方法在10.0μg/L~500μg/L范围内线性良好,方法检出限为1.6μg/L。用该方法测定实际水样,结果未检出。实际水样的3个质量浓度水平加标回收率为83.6%~104%,RSD为2.1%~8.3%。     

An investigation on biological stability of product water generated by lab-scale and pilot-scale distillation systems

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, 240}Pu,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.     

Metal concentrations in deciduous tree leaves from urban areas in Poland

Accumulation of metals in deciduous tree foliage fromurban areas in western-south Poland was monitored duringthe vegetation season of 2000 year. Concentrations of Al,Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sr, Ti and Znwere measured in birch, willow, linden and maple leavesusing the ICP-AES method. Seasonal variations of metalconcentrations and their relations with sampling sitewere investigated. The most dynamic accumulation of Al,Cd, Cr, Ni and Pb was observed for examined species. Thehighest differences in element concentrations forinvestigated sites were found for Ba, Cd, Mn and Ni.Interelement correlations were investigated. In allfoliar samples synergistic relationships between Al–Crand Ca-Sr were found. Statistically significant negativecorrelations were observed only for Cd and Ti in birch leaves.     

Varying Stable Nitrogen Isotope Ratios of Different Coastal Marsh Plants and Their Relationships with Wastewater Nitrogen and Land Use in New England, USA

The stable nitrogen isotope ratios of some biota have been used as indicators of sources of anthropogenic nitrogen. In this study the relationships of the stable nitrogen isotope ratios of marsh plants, Iva frutescens (L.), Phragmites australis (Cav.) Trin ex Steud, Spartina patens (Ait.) Muhl, Spartina alterniflora Loisel, Ulva lactuca (L.), and Enteromorpha intestinalis (L.) with wastewater nitrogen and land development in New England are described. Five of the six plant species (all but U. lactuca) showed significant relationships of increasing δ ¹⁵N values with increasing wastewater nitrogen. There was a significant (P < 0.0001) downward shift in the δ ¹⁵N of S. patens (6.0 ± 0.48‰) which is mycorrhizal compared with S. alterniflora (8.5 ± 0.41‰). The downward shift in δ ¹⁵N may be caused by the assimilation of fixed nitrogen in the roots of S. patens. P. australis within sites had wide ranges of δ ¹⁵N values, evidently influenced by the type of shoreline development or buffer at the upland border. In residential areas, the presence of a vegetated buffer (n = 24 locations) significantly (P < 0.001) reduced the δ ¹⁵N (mean = 7.4 ± 0.43‰) of the P. australis compared to stands where there was no buffer (mean = 10.9 ± 1.0‰; n = 15). Among the plant species, I. frutescens located near the upland border showed the most significant (R ² = 0.64; P = 0.006) inverse relationship with the percent agricultural land in the watershed. The δ ¹⁵N of P. australis and I. frustescens is apparently an indicator of local inputs near the upland border, while the δ ¹⁵N of Spartina relates with the integrated, watershed-sea nitrogen inputs.     

Radionuclide Concentrations in Benthic Invertebrates from Amchitka and Kiska Islands in the Aleutian Chain, Alaska

Concentrations of 13 radionuclides (¹³⁷Cs, ¹²⁹I, ⁶⁰Co, ¹⁵²Eu, ⁹⁰Sr, ⁹⁹Tc, ²⁴¹Am, ²³⁸Pu, ^239,249Pu, ²³⁴U, ²³⁵U, ²³⁶U, ²³⁸U were examined in seven species of invertebrates from Amchitka and Kiska Islands, in the Aleutian Chain of Alaska, using gamma spectroscopy, inductively coupled plasma mass spectroscopy, and alpha spectroscopy. Amchitka Island was the site of three underground nuclear test (1965–1971), and we tested the null hypotheses that there were no differences in radionuclide concentrations between Amchitka and the reference site (Kiska) and there were no differences among species. The only radionuclides where composite samples were above the Minimum Detectable Activity (MDA) were ¹³⁷Cs, ²⁴¹Am, ^239,249Pu, ²³⁴U, ²³⁵U, ²³⁶U, and ²³⁸U. Green sea urchin (Strongylocentrotus polyacanthus), giant chiton (Cryptochiton stelleri), plate limpets (Tectura scutum) and giant Pacific octopus (Enteroctopus dofleini) were only tested for ¹³⁷Cs; octopus was the only species with detectable levels of ¹³⁷Cs (0.262 ± 0.029 Bq/kg, wet weight). Only rock jingle (Pododesmus macroschisma), blue mussel (Mytilus trossulus) and horse mussel (Modiolus modiolus) were analyzed for the actinides. There were no interspecific differences in ²⁴¹Am and ^239,240Pu, and almost no samples above the MDA for ²³⁸Pu and ²³⁶U. Horse mussels had significantly higher concentrations of ²³⁴U (0.844 ± 0.804 Bq/kg) and ²³⁸U (0.730 ± 0.646) than the other species (both isotopes are naturally occurring). There were no differences in actinide concentrations between Amchitka and Kiska. In general, radionuclides in invertebrates from Amchitka were similar to those from uncontaminated sites in the Northern Hemisphere, and below those from the contaminated Irish Sea. There is a clear research need for authors to report the concentrations of radionuclides by species, rather than simply as ‘shellfish’, for comparative purposes in determining geographical patterns, understanding possible effects, and for estimating risk to humans from consuming different biota.     

Effect of heavy metal contaminated shooting range soils on mycorrhizal colonization of roots and metal uptake by leek

We grew leek (Allium porrum) in soils of two shooting ranges heavily contaminated with heavy metals in the towns of Zuchwil and Oberuzwil in Switzerland as a bioassay to test theactivity of arbuscular mycorrhizal (AM) fungi in these soils.Soil samples were taken from (1) front of the shooting house(HOUSE), (2) the area between house and target (FIELD) and (3) the berm (BACKSTOP). Samples of Ribwort plantain (Plantagolanceolata) growing naturally within the shooting ranges werealso collected and the colonization of its roots by mycorrhizalfungi was measured. The number of AM spores in the soils wassignificantly reduced concomitant with the increase in thedegree of soil contamination with metals. In Zuchwil,mycorrhizal fungi equally colonized roots of Ribwort plantainsampled from BACKSTOP and HOUSE. In Oberuzwil, however, plantsfrom BACKSTOP had lower colonization when compared with thosesampled from HOUSE. Colonization of leek was strongly reducedin the BACKSTOP soil of Zuchwil and slightly reduced in theBACKSTOP soil of Oberuzwil when compared with plants grown inrespective HOUSE soil. Concentrations of Cd, Cr, Cu, Ni, Pb andZn in the leaves of leek grown in the BACKSTOP soil was withinthe range considered toxic for human consumption. This pointsto the high degree of bio-availability of these metal in thesesoils. Significant decrease in the number of mycorrhizal sporesin the BACKSTOP soils in Zuchwil and the low colonization ofleek roots grown in these soils point to possible changes inthe species diversity of mycorrhizal fungi in these soils.     

Kelp as a Bioindicator: Does it Matter Which Part of 5 M Long Plant is Used for Metal Analysis?

Kelp may be useful as a bioindicator because they are primary producers that are eaten by higher trophic level organisms, including people and livestock. Often when kelp or other algae species are used as bioindicators, the whole organism is homogenized. However, some kelp can be over 25 m long from their holdfast to the tip of the blade, making it important to understand how contaminant levels vary throughout the plant. We compared the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in five different parts of the kelp Alaria nana to examine the variability of metal distribution. To be useful as a bioindicator, it is critical to know whether levels are constant throughout the kelp, or which part is the highest accumulator. Kelp were collected on Adak Island in the Aleutian Chain of Alaska from the Adak Harbor and Clam Cove, which opens onto the Bering Sea. In addition to determining if the levels differ in different parts of the kelp, we wanted to determine whether there were locational or size-related differences. Regression models indicated that between 14% and 43% of the variation in the levels of arsenic, cadmium, chromium, manganese, mercury, and selenium was explained by total length, part of the plant, and location (but not for lead). The main contributors to variability were length (for arsenic and selenium), location (mercury), and part of the plant (for arsenic, cadmium, chromium and manganese). The higher levels of selenium occurred at Clam Cove, while mercury was higher at the harbor. Where there was a significant difference among parts, the holdfast had the highest levels, although the differences were not great. These data indicate that consistency should be applied in selecting the part of kelp (and the length) to be used as a bioindicator. While any part of Alaria could be collected for some metals, for arsenic, cadmium, chromium, and manganese a conversion should be made among parts. In the Aleutians the holdfast can be perennial while the blade, whipped to pieces by winter wave action, is regrown each year. Thus the holdfast may be used for longer-term exposure for arsenic, cadmium, chromium and manganese, while the blade can be used for short-term exposure for all metals. Cadmium, lead and selenium were at levels that suggest that predators, including people, may be at risk from consuming Alaria. More attention should be devoted to heavy metal levels in kelp and other algae from Adak, particularly where they may play a role in a subsistence diets.     

Assessing Potential for Recovery of Biotic Richness and Indicator Species due to Changes in Acidic Deposition and Lake ph in Five Areas of Southeastern Canada

Biological damage to sensitive aquatic ecosystems is among the most recognisable, deleterious effects of acidic deposition. We compiled a large spatial database of over 2000 waterbodies across southeastern Canada from various federal, provincial and academic sources. Data for zooplankton, fish, macroinvertebrate (benthos) and loon species richness and occurrence were used to construct statistical models for lakes with varying pH, dissolved organic carbon content and lake size. pH changes, as described and predicted using the Integrated Assessment Model (Lam et al., 1998; Jeffries et al., 2000), were based on the range of emission reductions set forth in the Canada/US Air Quality Agreement (AQA). The scenarios tested include 1983, 1990, 1994 and 2010 sulphate deposition levels. Biotic models were developed for five regions in southeastern Canada (Algoma, Muskoka, and Sudbury, Ontario, southcentral Québec, and Kejimkujik, Nova Scotia) using regression tree, multiple linear regression and logistic regression analyses to make predictions about recovery after emission reductions. The analyses produced different indicator species in different regions, although some species showed consistent trends across regions. Generally, the greatest predicted recovery occurred during the final phase of emission reductions between 1994 and 2010 across all taxonomic groups and regions. The Ontario regions, on average, were predicted to recover to a greater extent than either southcentral Québec or the Kejimkujik area of Nova Scotia. Our results reconfirm that pH 5.5–6.0 is an important threshold below which damage to aquatic biota will remain a major local and regional environmental problem. This damage to biodiversity across trophic levels will persist well into the future if no further reductions in sulphate deposition are implemented.     

Nitrogen Content of Letharia vulpina Tissue from Forests of the Sierra Nevada, California: Geographic Patterns and Relationships to Ammonia Estimates and Climate

Nitrogen (N) pollution is a growing concern in forests of the greater Sierra Nevada, which lie downwind of the highly populated and agricultural Central Valley. Nitrogen content of Letharia vulpina tissue was analyzed from 38 sites using total Kjeldahl analysis to provide a preliminary assessment of N deposition patterns. Collections were co-located with plots where epiphytic macrolichen communities are used for estimating ammonia (NH₃) deposition. Tissue N ranged from 0.6% to 2.11% with the highest values occurring in the southwestern Sierra Nevada (range: 1.38 to 2.11). Tissue N at 17 plots was elevated, as defined by a threshold concentration of 1.03%. Stepwise regression was used to determine the best predictors of tissue N from among a variety of environmental variables. The best model consisted only of longitude (r ² = 0.64), which was reflected in the geographic distribution of tissue values: the southwestern Sierra Nevada, the high Sierras near the Tahoe Basin, and the Modoc Plateau, are three apparent N hotspots arranged along the tilted north–south axis of the study area. Withholding longitude and latitude, the best regression model suggested that NH₃ estimates and annual number of wetdays interactively affect N accumulation (r ² = 0.61; % N ∼ NH₃ + wetdays + (NH₃ × wetdays)). We did not expect perfect correspondence between tissue values and NH₃ estimates since other N pollutants also accumulate in the lichen thallus. Additionally, other factors potentially affecting N content, such as growth rate and leaching, were not given full account.     

Spatial Relationships Between Water Quality and Pesticide Application Rates in Agricultural Watersheds

Pesticide applications to agricultural lands in California, USA, are reported to a central data base, while data on water and sediment quality are collected by a number of monitoring programs. Data from both sources are geo-referenced, allowing spatial analysis of relationships between pesticide application rates and the chemical and biological condition of water bodies. This study collected data from 12 watersheds, selected to represent a range of pesticide usage. Water quality parameters were measured during six surveys of stream sites receiving runoff from the selected watershed areas. This study had three objectives: to evaluate the usefulness of pesticide application data in selecting regional monitoring sites, to provide information for generating and testing hypotheses about pesticide fate and effects, and to determine whether in-stream nitrate concentration was a useful surrogate indicator for regional monitoring of toxic substances. Significant correlations were observed between pesticide application rates and in-stream pesticide concentrations (p < 0.05) and toxicity (p < 0.10). In-stream nitrate concentrations were not significantly correlated with either the amount of pesticides applied, in-stream pesticide concentrations, or in-stream toxicity (all p > 0.30). Neither total watershed area nor the area in which pesticide usage was reported correlated significantly with the amount of pesticides applied, in-stream pesticide concentrations, or in-stream toxicity (all p > 0.14). In-stream pesticide concentrations and effects were more closely related to the intensity of pesticide use than to the area under cultivation.     

Heavy Metals and Selenium in Herring Gulls (LARUS ARGENTATUS) NESTING IN COLONIES FROM EASTERN LONG ISLAND TO VIRGINIA

With increasing interest in assessing the health or well-being ofcommunities and ecosystems, birds are being used asbioindicators. Coloniallynesting species breed mainly in coastal areas that are alsopreferred for humandevelopment, exposing the birds to various pollutants. Inthis paper concentrations of heavy metal and selenium in the feathers ofHerring Gulls(Larus argentatus) nesting in several colonies fromMassachusetts toDelaware are reported. There were significant differencesamong colonies forall metals, with metal concentrations being two to nearly fivetimes higher atsome colonies than others. Selenium showed the leastdifference, and cadmium showed the greatest difference among sites. Concentrations of lead werehighest at Pralls Island; mercury was highest at Shinnecock,Huckleberry andHarvey, and manganese was highest at Captree.