固相萃取-高效液相色谱法同时测定水中12种磺酰脲类除草剂

采用固相萃取-高效液相色谱法同时测定水中12种磺酰脲类除草剂,样品经磷酸调节pH值为2后,经Watens Oasis HLB SPE柱净化浓缩,乙腈洗脱,选择检测波长为230 nm,以乙腈-水溶液(0.02%磷酸)为流动相梯度洗脱,保留时间在14 min～32 min范围内.12种磺酰脲类除草剂在0.050 mg/L～...     

Effect of thiobencarb and pretilachlor on microorganisms in relation to mineralization of C and N in the Gangetic alluvial soil of West Bengal

An experiment was conducted under laboratory conditions to investigate the effect of two pre-emergence herbicides, viz., thiobencarb (at 1.5 and 4.5 kg active ingredient (a.i.) ha^?1) and pretilachlor (at 0.5 and 1.5 kg a.i. ha^?1), on the growth and multiplication of some microorganisms (bacteria, actinomycetes and fungi) in relation to transformations and availability of C and N in the Gangetic alluvial soil (Typic Haplustept) of West Bengal, India. Application of both the herbicides, in general, significantly increased microbial biomass, resulting in greater retention, mineralization and availability of oxidizable organic C and N in soil, and the stimulations were more pronounced when the herbicides were applied at their lower concentrations (recommended field application rates), more so with thiobencarb, as compared to pretilachlor. Compared to untreated control soil, the application of thiobencarb at lower concentration increased the proliferation of total bacteria, actinomycetes and fungi by 57.3, 36.6 and 55.2 %, respectively, and released the highest amount (40.2 %) of soluble NO₃ ^? in soil, while pretilachlor at field application rate induced the growth and multiplication of bacteria and fungi by 58.3 and 17.6 %, respectively. Irrespective of the concentrations, the stimulations were at par for both the herbicides towards the retention of oxidizable organic C, total N and exchangeable NH₄ ⁺ in soil.     

高效液相色谱法测定土壤中三嗪类除草剂

建立了索氏提取、中性氧化铝小柱净化、高效液相色谱二极管阵列检测器测定土壤中7种三嗪类除草剂的方法，优化了检测波长、提取方法和溶剂、梯度淋洗程序等试验条件。7种三嗪类除草剂在0．10mg／L～2．00mg／L范围内线性良好，检出限为0．84μg／kg～2．07μg／kg，RSD为1．2％～5．6％，加标回收率为95.0％～107％。     

A survey on the temporal and spatial distribution of perchlorate in the Potomac River

Samples of river water and treated drinking water were obtained from eight sites along the Potomac River between western Maryland and Washington DC. Samples were collected each month from October 2007 to September 2008 and analyzed for perchlorate by ion chromatography/mass spectrometry. Data on anions were also collected for seven of the twelve months. Data were analyzed to identify spatial and temporal patterns for the occurrence of perchlorate in the Potomac. Over the year of sampling, the largest monthly increase occurred from June to July, with levels then decreasing from July to September. Samples from the period between December and May had lower perchlorate concentrations, relative to the remainder of the study year. Spatially, higher levels of perchlorate were found at sites located in west-central Maryland, the eastern panhandle of West Virginia, and central northern Virginia, with levels decreasing slightly as the Potomac approaches Washington DC. Within the sampling boundaries, river (untreated) water perchlorate concentrations ranged from 0.03 μg L(-1) to 7.63 μg L(-1), averaged 0.67 ± 0.97 μg L(-1) over the year-long period and had a median value of 0.37 μg L(-1). There was no evidence that any of the existing drinking water treatment technologies at the sampling sites were effective in removing perchlorate. There were no correlations found between the presence of perchlorate and any of the anions or water quality parameters examined in the source water with the exception of a weak positive correlation with water temperature. Results from the summer (June-August) and fall (September-November) months sampled in this study were generally higher than from the winter and spring months (December-May). All but one of the locations had annual average perchlorate levels below 1 μg L(-1); however, 7 of the 8 sites sampled had river water perchlorate detections over 1 μg L(-1) and 5 of the 8 sites had treated water detections over this level.     

固相萃取气相色谱法测定水中15种硝基苯类化合物

使用Oasis HLB固相萃取柱,以正己烷/丙酮混合溶剂(体积比为3∶1)为洗脱溶剂,采用毛细管柱气相色谱电子捕获检测器同时测定水中15种硝基苯类化合物,以保留时间定性,外标标准曲线法定量。硝基苯和硝基甲苯在50.0μg/L～1 000μg/L、其他硝基苯类化合物在5.00μg/L～100μg/L范围内线性良好,检出限硝基苯和硝基甲苯为0.035μg/L～0.052μg/L,其他硝基苯类化合物为0.003 5μg/L～0.005 6μg/L,加标水样平行测定的RSD为1.4%～4.0%,平均回收率为92%～100%。     

Pesticide residue analysis of soil,water, and grain of IPM basmati rice

The main aim of the present investigations was to compare the pesticide load in integrated pest management (IPM) with non-IPM crops of rice fields. The harvest samples of Basmati rice grain, soil, and irrigation water, from IPM and non-IPM field trials, at villages in northern India, were analyzed using multi-pesticide residue method. The field experiments were conducted for three consecutive years (2008–2011) for the successful validation of the modules, synthesized for Basmati rice, at these locations. Residues of tricyclazole, propiconazole, hexconazole, lambda cyhalothrin, pretilachlor chlorpyrifos, DDVP, carbendazim, and imidacloprid were analyzed from two locations, Dudhli village of Dehradun, Uttrakhand and Saboli and Aterna village of Sonepat, Haryana. The pesticide residues were observed below detectable limit (BDL) (<0.001–0.05 μg/g) in all 24 samples of rice grains and soil under IPM and non-IPM trials. Residues were below detection level (<0.001–0.05 μg/L) in irrigation water samples (2008–09). Residues of tricyclazole and carbendazim, analyzed from same locations, revealed pesticide residues as BDL (<0.001–0.05 μg/g) in all 40 samples of Basmati rice grains and soil. It was also observed as BDL (<0.001–0.05 μg/L) for 12 water samples (2009–2010). The residues of tricyclazole, propioconazole, chlorpyrifos, hexaconazole, pretilachlor, and λ-cyhalothrin were also found as BDL (<0.001–0.05 μg/g) in 40 samples of Basmati rice grains and soil and 12 water samples (<0.001–0.05 μg/L) (2010–2011).     

高效液相色谱法测定稻田中丙草胺残留

用二氯甲烷提取稻田水和水稻植株样品中的丙草胺，稻田土壤样品用二氯甲烷-甲醇混合溶剂（体积比为9∶1）提取，再用高效液相色谱仪测定。方法在0．02 mg/L～2．00 mg/L的范围内线性良好，相关系数为0．9998；稻田水、土壤，水稻植株中丙草胺的检出限分别为0．001 mg/L、0．005 mg/kg、0．01 mg/kg；对稻田水、土壤和水稻植株分别做3个浓度水平的加标回收试验，重复5次，平均回收率在75．5％～84．7％之间，测定结果的相对标准偏差为2．0％～10．5％。     

离子色谱法测定地表水和饮用水中亚氯酸盐、溴酸盐和氯酸盐

采用KOH梯度淋洗离子色谱法测定地表水和饮用水中ClO2-、BrO3-和ClO3-，在试验确定的条件下，3种离子与F-、Cl-、NO2-、NO3-、SO2-4、Br-、I-等7种离子分离度良好。 ClO2-、BrO3-、ClO3-在50．0μg/L～1000μg/L范围内线性良好，检出限分别为5．2μg/L、8．9μg/L、7．6μg/L，环境水样加标平行测定的RSD分别为2．1％～5．4％、4．1％～5．4％、2．5％～4．8％，两个质量浓度水平加标的平均回收率分别为93．7％～96．5％、90．3％～94．8％、98．7％～111％。     

气相色谱-串联质谱法测定水中痕量有机磷农药和甲萘威

采用二氯甲烷萃取水样，气相色谱-串联质谱法同时测定水中有机磷农药和甲萘威。试验表明：方法在20．0μg/L ～1000μg/L范围内，各目标化合物线性良好；方法检出限为0．004μg/L～0．01μg/L；对实际水样进行3个质量浓度水平的加标回收试验，回收率在71．8％～94．5％之间，RSD为3．7％～8．5％，满足水中痕量有机磷农药和甲萘威的测定要求。     

Occurrence of selected antibiotics in Jiulongjiang River in various seasons, South China

The concentrations of six sulfonamides (SAs) and three tetracyclines (TCs) were investigated in Jiulongjiang River during the low water season and the high water season. They were monitored in both surface water and sediment. Total concentrations of all these antibiotics varied from 31 to 25,771 ng g(-1) in sediment samples. In water they ranged from 60 to 2607 ng L(-1) during the low water season and from ND (not detected) to 134 ng L(-1) during the high water season. At the sites nearby breeding farms, chlorotetracycline was found to have the highest concentration of 1036 ng L(-1) in water and 14,666 ng g(-1) in sediments. According to the published data, the concentrations of sulfamethazine, sulfameter and TCs at these sites were higher than that in most rivers. The concentrations during the low water season were tens to hundreds of times higher than that in the high water season. The lower concentrations of TCs in the high water season might result from both dilution and photo-degradation, while dilution and bio-degradation might lead to the lower concentrations of SAs. However, further study is needed to clarify the specific reasons. Concerning the relationship between sediment and water samples, the pseudo-partitioning values of TCs were much higher than SAs. It indicates that the TCs are prone to accumulate in the sediment.     

液液萃取-气质联用法测定饮用水源地水中SVOCs

采用乙酸乙酯-正己烷混合溶剂（体积比为2∶1）对饮用水源地水中阿特拉津、林丹、邻苯二甲酸二正丁酯（DBP）、邻苯二甲酸二（2-乙基己基）酯（DEHP）和滴滴涕（含4种）等8种半挥发性有机物进行1次水样萃取，用气质联用法同时测定。试验表明，方法在25．0μg/L～500μg/L范围内线性良好；检出限在0．006μg/L ～0．028μg/L 之间；空白水样3个质量浓度水平的加标回收率为87．6％～109％，平行测定6次的 RSD＜5．1％；测定集中式生活饮用水源地的实际水样，未检出目标化合物，加标回收率为98．6％～109％。     

液液萃取-气质联用法测定水中20种农药类有机物

采用液液萃取-气质联用法同时测定水中20种农药类有机物。对前处理过程中萃取剂的选择、用量，萃取时间，盐析剂用量，有机改进剂的加入等条件进行了优化，使得各组分在0．500μg/L～50．0μg/L范围内线性良好。方法检出限为0．02μg/L～0．19μg/L；平行测定7次混合标准溶液，RSD为0．3％～9．1％；对20种农药类有机物混合标准溶液进行加标回收试验，回收率为90．5％～110％。该方法优化了《生活饮用水标准检验方法》（ GB 5750-2006）中农药类有机污染物的检测方法，满足常规测定的要求。     

吹扫捕集-气质联用法测定水中9种酯类物质

采用吹扫捕集-气相色谱／质谱联用法测定水中9种酯类有机物，加入硫酸钠盐提高灵敏度，当硫酸钠过饱和时，吹扫捕集效率最高。9种酯类有机物在一定的质量浓度范围内线性关系良好，方法检出限为0．14μg／L～0．25μg／L，模拟样品平行测定的RSD为0．6％～1．8％，加标回收率为80％～106％。     

高效液相色谱-原子荧光光谱联用测定水中形态砷

采用高效液相色谱-氢化物发生-原子荧光光谱联用技术测定水中亚砷酸盐[As(Ⅲ)]、二甲基砷(DMA)、一甲基砷(MMA)和砷酸盐[As(V)]等4种形态砷,以磷酸盐缓冲溶液为流动相,硼氢化钾为还原剂,优化了仪器主要技术参数.As(Ⅲ)、DMA、MMA和As(V)在7 min内实现了良好的基线分离,在5.00 μg/L～...     

固相膜萃取-高效液相色谱法测定地下水中的多环芳烃

采用C18固相膜萃取对地下水中15种多环芳烃进行富集净化，以二氯甲烷作洗脱溶剂，高效液相色谱法，荧光检测器测定。对萃取、浓缩和色谱条件进行优化，在1．ooixg／L～40．0μg／L范围内测定标准系列溶液并绘制标准曲线，相关系数R2〉0．999；15种多环芳烃的仪器检出限为0．4ng／L～3．0ng／L；对地下水样品加标，平均回收率在75．7％～96．7％之间；标准溶液平行测定7次的RSD为3．1％～11．9％。     

地表水样品中10种卤代烃测定方法的优化

对地表水样品中10种卤代烃测定方法进行优化,找出空白偏高的原因。方法优化后的加标回收率为90.1%~104%,相对标准偏差为1.1%~6.9%,检出限为0.000 3μg/L~2.0μg/L,可满足地表水环境质量分析要求。     

HPLC-ICP/MS联用测定废水中甲基汞和无机汞

采用高效液相色谱(HPLC)-电感耦合等离子体质谱(ICP/MS)联用测定废水中可滤态的甲基汞和无机汞,优化了仪器工作条件,讨论了方法干扰及校正办法。甲基汞和无机汞在0.500μg/L~25.0μg/L范围内线性良好,检出限分别为0.03μg/L和0.07μg/L,废水样品平行测定的RSD分别为6.5%~7.6%和6.2%~6.8%,加标回收率分别为84.0%~87.0%和88.0%~92.4%。     

Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California

Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98-58.0 μg Se/g; midge larvae, 12.7-50.6 μg Se/g; mosquitofish, 13.2-20.2 μg Se/g; and mollies, 12.8-30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.     

Regulation of the dissolved phosphate concentration of a mountainous stream, Kitakyushu, southwestern Japan

The phosphate concentration in mountainous stream water can be a measure of the forest condition, because its concentration will be low when the biomass in the forest is increasing and vice versa when the forest is declining. To investigate the seasonal change in the dissolved phosphate concentration of the mountainous stream water of the Yamakami River, Kitakyushu, from June 2009 to August 2010, and the regulation mechanism of the phosphate concentration, solid-phase spectrophotometry, which can be applicable to natural water without any pretreatment procedures, was employed for the determination of phosphate at μg P L(-1) levels in natural water. The phosphate concentrations in the mountainous stream waters at 6 sites ranged from 2.2 to 13 μg P L(-1), and those from the catchment area of the steady state forest were 5.3 ± 1.6 (±1 SD) μg P L(-1). Changes in the concentration were fairly small even during a storm runoff. The average phosphate concentration of rain was 2.8 ± 0.7 μg P L(-1), about half of the concentration in the stream water. The rate of runoff in forest areas is generally considered to be about 50% of the total precipitation. For a forest under a climax condition, the phosphate concentration is estimated to be regulated by the fallout and evapotranspiration (α = 0.05). At one of the sites, an upstream tributary, where a fairly big landslide occurred before July in 2009, the phosphate concentration was the highest, suggesting that the biomass may still be decreasing. For all of the six sites examined, a characteristic seasonal change in phosphate concentration was observed, reflecting the local budget between the biological decomposition of plant matter and the consumption by the biomass. The increase in the phosphate concentration during late spring and early summer may result from the extensive decomposition of plant litter mainly supplied in autumn and of plant matter relating to spring blooming such as fallen flowers, pollen and immature fruits. The proposed method using the phosphate concentration in surface stream waters without the period of the seasonal change mentioned above is expected to be very helpful in diagnosing the condition of forests.     

Water and sediment quality of dry season pools in a dryland river system: the upper Leichhardt River, Queensland, Australia

This article presents the geochemical characteristics and physicochemical properties of water and sediment from twelve semi-permanent, dryland pools in the upper Leichhardt River catchment, north-west Queensland, Australia. The pools were examined to better understand the quality of sediments and temporary waters in a dryland system with a well-established metal contamination problem. Water and sediment sampling was conducted at the beginning of the hydroperiod in May and September 2007. Water samples were analyzed for major solute compositions (Ca, Na, K, Mg, Cl, SO(4), HCO(3)) and water-soluble (operationally defined as the <0.45 μm fraction) metals (Cd, Cu, Pb, Zn). Sediment samples were analyzed for total extractable and bioaccessible metals (As, Cd, Cu, Pb, Zn), elemental composition and grain morphology. At the time of sampling a number of pools contained water and sediment with elevated concentrations, compared to Australian regulatory guidelines, of Cu (maximum: water 28 μg L(-1); sediment 770 mg kg(-1)), Pb (maximum: water 3.4 μg L(-1); sediment 630 mg kg(-1)) and Zn (maximum: water 150 μg L(-1); sediment 780 mg kg(-1)). Concentrations of Cd and As in pools were relatively low and generally within Australian regulatory guideline values. Localized factors, such as the interaction of waters with anthropogenic contaminants from modern and historic mine wastes (i.e. residual smelter and slag materials), exert influence on the quality of pool waters. Although the pools of the upper Leichhardt River catchment are contaminated, they do not appear to be the primary repository of water and sediment associated metals when compared to materials in the remainder channel and floodplain. Nevertheless, a precautionary approach should be adopted to mitigating human exposure to contaminated environments, which might include the installation of appropriate warning signs by local health and environmental authorities.