HPLC法测定饲料中维生素A、维生素D 3 和维生素E

建立了以w(C2H5OH)=95 %乙醇直接提取,高效液相色谱仪在波长280 nm和254 nm处连续测定饲料中维生素A、维生素D3和维生素E的方法.色谱柱为大连依利特Hypersil ODS C18(25 cm×4.6 mm×5 μm),流动相为甲醇-水,流速为1.2 mL/min.维生素A、维生素D3、维生素E的质量浓度分别在1.0 mg/L～20.0 mg/L、0.5 mg/L～15.0 mg/L 、2.5 mg/L～50.0 mg/L范围内与峰面积呈良好的线性关系,检测限分别为0.3×10-6 μg、0.04×10-6 μg、5.0×10-6 μg,相对标准偏差分别为1.6 %、2.7 %、2.4 %,平均回收率分别为99 %、102 %、98 %.     

反向流动注射化学发光测定微量甲醛

基于在甲醛存在下 ,高锰酸钾与Fe(Ⅱ )在酸性介质中发生化学发光反应 ,建立了反向流动注射化学发光测定微量的甲醛分析方法 ,该法测定甲醛的线性范围为 5 0× 10 - 7～ 1 5× 10 - 2 g ml,检出限为 3 0× 10 - 7g ml,相对标准偏差为2 5 % (1 5× 10 - 5g ml甲醛 ,n =11)。该法应用于测定空气中微量的甲醛 ,结果令人满意。     

分析大气中氟化物含量的测量时间

1测水氟时发现氟电极的响应速度与待测溶液的浓度有关 ,溶液越稀 ,电极响应时间越长 ;溶液越浓 ,电极响应时间越短。理论上有 F-浓度为1 0 - 6 ～ 5× 1 0 - 7M时 ,电极响应时间小于 5分钟 ;而在 F- 浓度为 1 0 - 3～ 1 0 - 6 M时 ,电极响应时间小于 2分钟。但实际分析发现电极响应时间会比理论略长一些。2根据这一规律 ,溶液较稀时可适当增加测量时间 ,溶液较浓时则可缩短测量时间。如在做试剂空白和全程序空白时 ,搅拌 1 0分钟 ,静置 1～ 2分钟后读数 ;而标准曲线的其他样品F-浓度为 1 .2× 1 0 - 6～ 6× 1 0 - 5M,搅拌 5分钟基本都可…     

碘量法快速测定烟气SO2

YQ- 2型烟气采样机 ;1 2 5ml玻璃筛板吸收瓶。在吸收瓶中装适量吸收液 ,定量加碘标准使用液 ( 0 .0 0 5mol/L) ,使总体积为 50 ml,加 0 .5%淀粉溶液 1 ml,以 0 .5L/min采样。采样至吸收液由兰色变无色时关机并记录采样时间及流量计前温度、压力。按下式计算 SO2 浓度 :SO2 ( mg/Nm3 ) =( C× V1× 6 4× 1 0 0 0 ) /V0　　式中 C为 I2 标液浓度 ( mol/L) ;V1为 I2 标液用量 ( ml) ;V0 为标态下烟气采样体积 ( L) ;6 4为SO2 摩尔质量 ( g)。本法与标准方法相对偏差0 .3%～ 3.2 % ,两法结果无显著性差异。碘量法快速测定烟气SO_2@张…     

接种稀释法测定BOD5方法改进

1稀释水质量 :DO为 9左右 ,1 L水中营养液加入量 1 ml,p H7.2 ,BOD50 .0 5 0～ 0 .2 0 0 mg/L。 2接种稀释水质量 :1 L稀释水中接种液加入量 ( mg/L) :河水上清液 1 0 0～ 2 0 0 ;生活污水上清液 2 0～ 30 ;植物表层浸出液 30～ 5 0。BOD50 .40 0～ 0 .80 0 mg/L。 3水样稀释倍数确定 :2 0℃时 ,五天培养前后消耗溶解氧 3.6～ 6.3mg/L,样品取样量 :V1=6.3× 1 0 0 0 /BOD估值 ;V2 =3. 6×1 0 0 0 /BOD估值。稀释倍数 δ1=1 0 0 0 /V1,δ2 =1 0 0 0 /V2 。 4计量器具和操作 :移液管取样 ,容量瓶定容 ,转入烧杯静置平衡。接种稀释法…     

吹扫—捕集/气相色谱法测定水中挥发性卤代烃

建立了吹扫—捕集 /气相色谱 /电子捕获检测器联用测定水中 5种挥发性卤代烃分析方法 ,且按国家水质分析标准方法 (GB/T 1 71 3 0 -1 997)所确定的三氯甲烷、四氯化碳、三氯乙烯、四氯乙烯、三溴甲烷 5种挥发性卤代烃进行实验 ,采用 Supelcoport担体层析柱对去离子水处理 ,所获得的纯水无色谱干扰峰 ,本法按国家水质分析标准方法列出的 5种挥发性卤代烃进行测定在国内尚未见报导。当纯水的进样体积为 5 .0 ml时 ,其最低检出浓度为 1× 1 0 - 2～ 6× 1 0 - 4(μg/L)之间 ;相对误差在 1 .1 %～ 2 .4%之间 ;加标回收率在 82 .5 %～ 1 0 8%之间 ;相关系数在 0 .9980～ 0 .9999之间。可快速、高灵敏度、简便、准确、精密地测定水中 5种挥发性卤代烃 ,本法适用于饮用水和地表水中挥发性卤代烃的测定     

HDNPTT与镉显色反应的研究

应用合成的新试剂 1- (2 -羟基 - 3 ,5 -二硝基苯 ) - 3 - (4 -苯基 - 2 -噻唑 ) -三氮烯 (HDNPTT) ,研究了在表面活性剂TritonX - 10 0存在下 ,它与Cd2 的显色反应。结果表明 ,在 pH 8 0～ 10 0范围内 ,Cd2 与该试剂形成的配合物 ,其最大吸收峰位于 5 35nm处 ,摩尔吸光系数为 1 89× 10 5L·mol-1·cm-1。Cd2 在 0mg/L～ 0 32mg/L范围内符合比尔定律。此法用于环境水样和人发样品中微量镉的测定 ,结果满意。     

褪色光度法测定微量碘的研究

研究了在硫酸介质中、溴化钾催化下 ,碘酸根氧化酸性铬蓝K褪色的最佳条件。其最大吸收波长λmax为 5 2 0nm ,表观摩尔吸光系数为 1 .1× 1 0 4 L·mol- 1·cm- 1,碘浓度在 0～ 3 .6mg/L内呈线性关系。方法用于测定加碘食盐中的碘 ,结果令人满意     

4-氨基安替吡啉法测定水中高浓度挥发酚

取 2 50 ml含酚水样的蒸馏液于 50 0 ml分液漏斗中 ,加入 2 .0 ml缓冲溶液混匀 ,此时 p H为1 0 .0± 0 .2。加入 1 .5ml2 % 4 - AAP溶液混匀 ,再加 1 .5ml铁氰化钾溶液混匀。做一试剂空白 ,然后均以蒸馏水为参比 ,显色 1 5min用 1 cm比色皿于波长 51 0 nm处测吸光度。含酚 0～ 50 0 (μg/2 50 ml)时符合比耳定律 ;摩尔吸光系数 1 .2 6×1 0 4L/mol· cm,灵敏度较高 ;检出限为 0 .0 75mg/L;相对标准误差 2 .75% ;回收率 92 .5～ 96 .7( % )。本法在经过显色剂显色后确定水样为高浓度时 ,只需对其直接比色即可测出挥发酚浓度 ,避免重复工作…     

气动进样原子荧光法测定环境水样中痕量汞和砷

以硼氢化钾作为还原剂原子荧光法测定环境水样中的汞和砷,配合以气动进样,方法简单、试剂用量少、灵敏度高.测汞时KBH4-KOH浓度为0.01%～0.0005%,样品中王水浓度3%(v/v),检测限为5.8×10-3μg/L;测砷时KBH4-KOH浓度为2.6%～1.0%,样品中盐酸浓度5%(v/v),检测限为4.9μg/L.     

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.     

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.     

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.     

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.