含砷废水消解方法

用二乙氨基二硫代甲酸银光度法测定工业废水中砷,在样品消解时齐水加入HNO3与消解至无水后再加入HNO3,所消耗的HNO3量相差十分大。试验表明,在通风橱内消解至产生白色烟雾,再加入05mlHNO3,直至溶液澄清,结果每样仅耗HNO310ml,所耗时间也短。而同样的样品按标准法齐水需加入55mlHNO3,时间还长。两种方法的测试结果相似。所以,硝酸最好在消解至无水时加入,这样可提高HNO3的氧化效率,节省化验成本。含砷废水消解方法@刘兴安$佛山市环境监测站!广东佛山528000     

原子荧光法测定土壤中砷前处理方法影响因素的研究

针对方法(GB/T 22105.2—2008)中土壤样品前处理过程中影响砷测定结果的因素进行了各类批次实验,得出各种因素对结果的影响程度及其消解的最佳条件。土壤样品的最佳称量范围为0.2～0.6g,消解液加入量的最佳范围为10～15ml,最佳消解时间为2h,硫脲溶液和抗坏血酸溶液的加入量必须满足20～30ml的条件,样品中加入还原剂后,静置时间不得低于20min,通常为30min。     

微波消解-ICP/MS法同时测定鱼肉中的砷和汞

采用微波消解处理鱼肉样品,用电感耦合等离子体质谱法测定样品中砷和汞。通过试验优化微波消解参数、酸体系及赶酸温度,用在线加入内标方法消除基体干扰及仪器漂移对测定的影响。方法在0μg/L～40. 0μg/L范围内线性良好,砷和汞的方法检出限分别为0. 002 mg/kg和0. 001 mg/kg,实际样品6次测定结果的RSD为5. 4%～15. 6%,加标回收率为90. 0%～110%。将该方法用于测定芹菜和扇贝标准物质,测定值在标准值不确定度范围内。     

氢化物发生——原子吸收法测定人发中砷

应用自制氢化物发生才电加热石英管原子吸收仪测定人发中砷。用硝酸－高氯酸进行消解，加入碘化钾溶液、抗坏血酸－硫脲混合液，消除了各种元素的干扰。方法简便快速、灵敏度高。发样砷的方法检测限为０．０３ｍｇ／ｋｇ，相对标准偏差在２．５％以内。     

微波消解-氢化物发生原子荧光法测定植物中汞和砷

采用微波消解-氢化物发生原子荧光法测定植物中汞和砷，优化了试验条件。汞在0μg／L-1．00μg／L、砷在0μg／L～20．0μg/L范围内线性良好，方法检出限汞为0．005mg／kg（以取0．1g样品消解定容至10mL计），砷为0．010mg／kg（以取0．1g样品消解定容至25mL计），植物样品测定的RSD≤4．5％，加标回收率为90．0％～107％。     

微波消解-原子荧光法测定环境空气中的砷

建立了浸渍滤膜吸附-微波消解-原子荧光法测定环境空气中的砷的方法，改进了原有的采样方法，有效地克服了原方法中湿法消解的缺点，并大大降低了检出限，能够满足《环境空气质量标准》（GB3095—2012）中对砷排放的参考浓度限值要求。     

过硫酸钠同时消解养殖尾水中总氮和总磷的探索

大部分池塘养殖尾水中总氮、总磷质量浓度偏高,测定过程中需要对样品进行稀释,耗时较长且影响准确度。实验室分析时,通常采用过硫酸钾对尾水样品进行消解,其配置过程对温度要求较高,易析出晶体,且耗时较长。而过硫酸钠易溶于水,受温度影响较小,易配制。因此,分别采用上述2种过硫酸盐消解液对样品进行消解并同时测定总氮、总磷的质量浓度,比较2种消解方式对校准曲线、加标回收率、养殖尾水实际样品测定的影响。结果表明,等质量或等物质的量的过硫酸钠消解液均能满足总氮、总磷的消解要求,且后者消解样品无须改变氢氧化钠的加入量和调整pH值,即可达到同等消解效果。因此,可采用等物质的量的过硫酸钠代替过硫酸钾同时消解养殖尾水中的总氮、总磷。     

氢化物发生-原子荧光法同时测定水中的砷和铅的研究

目的是建立一种同时测定水中微量砷和铅的方法。方法采用酸消解法消解水样,氢化物发生-原子荧光法同时测定水中微量砷和铅。结果显示,砷和铅方法的检出限分别为0.20μg/L和0.24μg/L,回收率分别为92.9%~104.4%和93.5%~103.8%,相对标准偏差分别为2.3%和3.5%。水中微量砷和铅用氢化物发生-原子荧光法测定能满足要求,可以同时测定。     

全自动石墨消解-原子荧光法测定土壤中砷和汞

采用全自动石墨消解仪代替水浴锅加热王水消解法处理土壤样品,用原子荧光法测定消解液中的砷和汞。该方法在0μg/L~20.0μg/L范围内线性良好,测定有证标准土壤样品的结果均在标准值允许范围内,砷、汞测定结果的RSD分别为2.5%~4.8%、2.9%~5.4%,比王水消解法的测定结果更靠近标准值,实际土壤样品的加标回收率分别为94.6%~104%、92.6%~105%。     

在同一消解液中同时测定总磷和总氮

探讨了在同一消解液中同时测定总磷、总氮的分析方法。实验结果表明，选用合适的氢氧化钠和过硫酸钾的加入量，可在同一消解液中同时测定总磷和总氮，并能克服消解液保存时间短的缺点。应用本文所拟最佳条件对标样和水样进行分析，结果准确，方法实用。     

Seasonal variation of oxidative stress biomarkers in clams Ruditapes decussatus sampled from Tunisian coastal areas

Seven (7) sites from to the Tunisian coastal area were monitored through four seasons using several oxidative stress biomarkers including lipid peroxidation. Catalase (CAT) specific activity was determined in clam Ruditapes decussatus digestive gland. Lipid peroxidation was assessed in the same tissues using malondialdehyde (MDA) concentration, neutral lipid (NL) and lipofuscin accumulation. Results show that catalase specific activity varies between sites and fluctuates in time. The highest CAT activities were recorded in sites from Bizerta Lagoon and sites neighbouring Sfax city. Malondialdehyde accumulation in digestive gland cells seems to be very pronounced in animals sampled in summer and autumn. Digestive gland sections of clams sampled from reported heavy metal polluted sites exhibited higher volume density of residual bodies. Our results showed that the neutral lipids and lipofuscin content in clam's digestive gland are more sensitive to general stress as compared to other biomarkers, and could be used successfully in clams as early warning tools in field biomonitoring programs.     

Acetylcholinesterase activity in Corbicula fluminea Mull., as a biomarker of organophosphate pesticide pollution in Pinacanauan River, Philippines

Organophosphates are known to inhibit the enzyme acetylcholinesterase. In this study, the AChE activity from the total soft tissues of Corbicula fluminea Mull. was used as a biomarker of organophosphate pollution in Pinacanauan River. Clams were collected from two different sites and at different seasons of the year. A colorimetric assay on the total soft tissues of the clams showed a directly proportional relationship between enzyme activity and condition of the riverine system. In vitro experiments on the total soft tissue, adductor muscles, digestive glands, and gills were conducted to assess the degree of localization of AChE as well as the sensitivity and tolerance of the enzymes in these tissues to varying concentrations of malathion. The degree of enzyme localization from highest to lowest is as follows: adductor muscle > gills > digestive gland whereas sensitivity to OP from greatest to least is: gills > adductor muscles > digestive gland.     

Metal Accumulation by Riverine and Lacustrine Populations of Angulyagra Oxytropis (Benson) (Gastropoda : Viviparidae)

Cadmium, chromium, iron, manganese, nickel, lead and zinc concentrations were determined in sediment and body tissues, viz. digestive gland, mantle and shell, of the freshwater snail, Angulyagra oxytropis (Benson) (Gastropoda : Viviparidae), from River Barak and one of its floodplain lakes in Cachar district, Assam State, Northeastern India. The concentrations of all the metals except iron are significantly higher in the lake sediment. When compared to their riverine counterparts, the lacustrine snails contain higher concentrations of cadmium, chromium and iron in their mantle; nickel and zinc in digestive gland; manganese in both digestive gland and mantle; and lead in all the three tissues examined. The accumulation patterns of most of the metals varied considerably between the two sites. The implications of these findings in storage, sequestration and detoxification of metals by this animal are discussed. The study also indicates that A. oxytropis may be a potential biological indicator of metal contamination in freshwater ecosystems.     

Interspecific and geographical variations of trace metal concentrations in cephalopods from Tunisian waters

The concentrations of six metals (Ag, Cd, Cu, Hg, Pb, and Zn) were investigated and compared in three tissues (arms, digestive gland, and mantle) of three cephalopod species from the Tunisian waters: the common octopus (Octopus vulgaris), the common cuttlefish (Sepia officinalis), and the European squid (Loligo vulgaris). Whatever the species or the sites, the digestive gland displayed the highest concentrations of Ag, Cd, Cu, Pb, and Zn, highlighting its major role in their bioaccumulation and detoxification. This is also true for Hg but only for the digestive gland of O. vulgaris. Muscle from the arms and the mantle contained thus relatively low trace metal concentrations except for Hg in L. vulgaris and S. officinalis. Geographic comparison of metal concentrations in Tunisian cephalopods from three locations indicates that higher concentrations of Ag, Pb, and Hg were observed in cephalopods from northern and eastern coasts, whereas the highest Cd levels were detected in the southeastern, reflecting different conditions of exposure. Comparing the trace element concentrations between species, Ag, Cd, Cu, Hg, and Zn concentrations were the highest in the digestive gland of octopuses. This may be related to the differences in ecological features and swimming behavior among different cephalopod species. Effects of length and sex on metal levels were also considered, indicating a limited influence of sex on metal concentration.     

Application of a battery of biomarkers in mussel digestive gland to assess long-term effects of the Prestige oil spill in Galicia and Bay of Biscay: tissue-level biomarkers and histopathology

In order to assess the biological effects of the Prestige oil spill (POS), mussels, Mytilus galloprovincialis, were collected in 22 localities along the North coast of the Iberian Peninsula over 3 years (April 2003-April 2006). Different tissue-level biomarkers including cell type composition (volume density of basophilic cells, Vv(BAS)) in digestive gland epithelium, structural changes of digestive alveoli (mean luminal radius to mean epithelial thickness, MLR/MET) and histopathological alterations (prevalence and intensity) of the digestive gland were analysed. Severe alterations in the general condition of the digestive gland tissue were observed all over the study area up to 2004-2005. High Vv(BAS) values were recorded mainly in Galicia but also to a lesser extent in the Bay of Biscay in 2003-2004. Atrophy of the digestive alveoli, measured in terms of MLR/MET, was detected all along the studied area up to 2006. Inflammatory responses cannot be related to pollution due to the POS: (a) prevalence and intensity of focal hemocytic infiltration were higher in the Bay of Biscay than in Galicia but they did not show a clear temporal trend; (b) high intensities of brown cell aggregates were only sporadically recorded; and (c) granulocytomas were more frequently recorded in the Bay of Biscay than in Galicia and especially in localities (i.e. Arrigunaga) subjected to chronic pollution. Likewise, Marteilia, trematodes, intracellular ciliates, unidentified eosinophilic bodies, R/CLO and Mytilicola did not follow any recognisable pattern that could be associated to the POS. In contrast, high Nematopsis intensities recorded in several localities in 2003 might suggest some response of local interest after the POS (i.e., in combination with particular factors/conditions). More data at a regional scale are needed before histopathology may provide a reliable ecosystem health assessment but the present results suggest that the approach is worthwhile. Overall, although Vv(BAS) returned to reference values by 2004-2005, MLR/MET values indicated that the mussel health condition was affected during the whole study period up to April 2006.     

利用H ach仪器开发低浓度COD的测试方法

利用Hach仪器开发了0 mg/L～150 mg/L COD的测试方法.采用反应器消解,比色法测定,配制的消解液能保证样品消解过程中浓硫酸和催化剂的含量与国标法相当,通过150 mg/L COD样品消解结束后重铬酸根离子半电池反应的电位折中确定重铬酸钾浓度.校准曲线线性关系良好,方法检出限为7 mg/L,与国标法作比较,结果表明两种方法可替换使用.     

Heavy metals in Patella caerulea (Mollusca, Gastropoda) in polluted and non-polluted areas from the Iskenderun Gulf (Mediterranean Turkey)

The concentrations of Cd, Cu, Zn, Fe, Pb, Ni, and Co were measured in gastropod mollusks Patella caerulea in the Mediterranean area. The organisms were collected at two coastal sites in Iskenderun Gulf during winter, spring, summer, and autumn 2008. Samples of the digestive gland, gill, and muscle were analyzed for heavy metals. The aim of study is to determine heavy metal levels in tissues of P. caerulea in different locations. Tissues of P. caerulea from the polluted site showed metal concentrations appreciably higher than unpolluted organisms. The highest metal levels were registered in the digestive gland of P. caerulea. Generally, digestive gland and gills showed higher metal concentrations than muscle. The average concentrations of heavy metals analyzed exhibited the following decreasing order: Fe > Zn > Cu > Ni > Cd > Pb > Co for both stations 1 and 2. Seasonal changes in metal concentrations were observed in the tissues of P. caerulea from a polluted and an unpolluted population.     

Status of Heavy Metals in Water and Bed Sediments of River Gomti – A Tributary of the Ganga River, India

The concentrations of cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc in water and bed sediments of river Gomti have been studied in a fairly long stretch of 500 km from Neemsar to Jaunpur. Grab samples of water (October 2002–March 2003) and bed sediments (December 2002 and March 2003) were collected from 10 different locations following the standard methods. The river water and sediment samples were processed and analyzed for heavy metals viz., Cd, Cr, Cu, Fe, Pb, Mn, Ni, and Zn, and using ICP-AES. The heavy metals found in the river water were in the range: Cd (0.0001–0.0005 mg/L); Cr (0.0015–0.0688 mg/L); Cu (0.0013–0.0.0043 mg/L); Fe (0.0791–0.3190 mg/L); Mn (0.0038–0.0.0973 mg/L); Ni (0.0066–0.011 mg/L); Pb (0.0158–0.0276 mg/L); and Zn (0.0144–0.0298 mg/L) respectively. In the sediments the same were found in the range: Cd (0.70–7.90 g/g); Cr (6.105–20.595 g/g); Cu (3.735–35.68 g/g); Fe (5051.485–8291.485 g/g); Mn (134.915–320.45 g/g); Ni (13.905–37.370 g/g); Pb (21.25–92.15 g/g); and Zn (15.72–99.35 g/g) of dry weight respectively. Some physico-chemical parameters viz., pH, total solids, total dissolved solids, total suspended solids, dissolved oxygen, biological oxygen demand, chemical oxygen demand, hardness etc. were estimated as these have direct or indirect influence on the incidence, transport and speciation of the heavy metals. Based on the geoaccumulation indices, the Gomti river sediments from Neemsar to Jaunpur are considered to be unpolluted with respect to Cr, Cu, Fe, Mn, and Zn. It is unpolluted to moderately polluted with Pb. In case of Cd it varies from moderately polluted to highly polluted. As far as Ni is concerned the sediment is very highly polluted at Barabanki and Jaunpur D/s. No correlation was found between enrichment factor and geoaccumulation index.     

The Bear Brook Watershed, Maine (BBWM), USA

The Bear Brook Watershed Manipulation project in Maine is a paired calibrated watershed study funded by the U. S. EPA. The research program is evaluating whole ecosystem response to elevated inputs of acidifying chemicals. The project consists of a 2.5 year calibration period (1987-1989), nine years of chemical additions of (NH4)2SO4 (15N- and 34S-enriched for several years) to West Bear watershed (1989-1998), followed by a recovery period. The other watershed, East Bear, serves as a reference. Dosing is in six equal treatments/yr of 1800 eq SO4 and NH4/ha/yr, a 200% increase over 1988 loading (wet plus dry) for SO4 and 300% for N (wet NO3 + NH4). The experimental and reference watersheds are forested with mixed hard- and softwoods, and have thin acidic soils, areas of 10.2 and 10.7 ha, and relief of 210 m. Thin till of variable composition is underlain by metasedimentary pelitic rocks and calc-silicate gneiss intruded by granite dikes and sills. For the period 1987-1995, precipitation averaged 1.4 m/yr, had a mean pH of 4.5, with SO4, NO3, and NH4 concentrations of 26, 14, and 7 eq/L, respectively. The nearly perrenial streams draining each watershed have discharges ranging from 0 (East Bear stops flowing for one to two months per year) to 150 L/sec. Prior to manipulation, East Bear and West Bear had a volume weighted annual mean pH of approximately 5.4, alkalinity = 0 to 4 eq/L, total base cations = 184 eq/L (sea-salt corrected = 118 eq/L), and SO4 = 100 to 111 eq/L. Nitrate ranged from 0 to 30 eq/L with an annual mean of 6 to 25 eq/L; dissolved organic carbon (DOC) ranged from 1 to 7 mg/L but was typically less than 3. Episodic acidification occurred at high discharge and was caused by dilution of cations, slightly increased DOC, significantly higher NO3, and the sea-salt effect. Depressions in pH were accompanied by increases in inorganic Al. The West Bear catchment responded to the chemical additions with increased export of base cations, Al, SO4, NO3, and decreased pH, ANC, and DOC. Silica remained relatively constant. Neutralization of the acidifying chemicals occurred dominantly by cation desorption and mobilization of Al.     

Simultaneous determination of parathion and p-nitrophenol in vegetable tissues by derivative spectrophotometry

A first derivative spectrophotometric method has been developedfor the determination of parathion and p-nitrophenol in vegetabletissues. Ethanol was used as solvent for extracting the compoundsfrom the tissues and subsequently the samples were evaluated against a vegetable tissue blank, directly by derivative spectrophotometry. The simultaneous determination of these compounds can be carried out using the zero-crossing approach for parathion at 253.0 nm and for p-nitrophenol at 273.1 nm. In the samples each analyte was determined in the presence of one another in the ranges between 4.9 to 3883.5 g g^-1 forparathion and 4.9 to 3285.3 g g^-1 for p-nitrophenol.The detection limits (3) were found to be 1.5 and 1.4 g g^-1 for parathion and p-nitrophenol, respectively. The relative standard deviations were in all instances less than1.8%. The proposed method was applied to the determination ofthe analytes in spiked leafs of corn. The results show a goodrecovery and they are in agreement with those obtained bypolarography.