恶唑酰草胺在稻田中的残留及消解动态

借助加速溶剂提取、凝胶渗透色谱净化和液相色谱测定方法,研究了南京和南昌两地稻田施用w为10%的恶唑酰草胺乳油后,其有效成分恶唑酰草胺在稻田中的残留及消解动态。结果表明,恶唑酰草胺在水稻植株、稻田土壤及稻田水中的消解较快,在南京和南昌两地水稻植株中的消解半衰期分别为3.5和2.2 d,在稻田土壤中的消解半衰期分别为11.7和20.2 d,在稻田水中的消解半衰期分别为1.3和2.3 d。在稻田中按照最高推荐剂量和最高推荐剂量的2倍施用恶唑酰草胺乳油,施药1次,在收获的稻秆、稻壳、糙米及稻田土壤中均未检出恶唑酰草胺。这说明恶唑酰草胺为低残留、易降解农药。     

典型有机磷酸酯阻燃剂分析方法研究进展

有机磷酸酯(OPEs)是一类重要的有机磷阻燃剂,近些年逐渐取代了溴代阻燃剂,广泛应用于各行各业,也因此导致在多种环境介质中有较高的暴露量和潜在风险。已有研究表明,OPEs具有一定的毒理效应,对人体及其他生物均有潜在危害。本文综述了近年来国内外OPEs的检测技术,详述了不同环境介质OPEs的前处理方法。结果表明,目前固相萃取(SPE)和固相微萃取(SPME)仍是水样前处理的主要方法;对于固体样品,加速溶剂萃取/加压液相萃取(ASE/PLE)和微波辅助萃取(MAE)应用较多;虽然大气样品仍以固体吸附剂方式为主,但已向在线一体化方向发展;而生物样品的前处理方法多与水样和固体样品方法相似;但是对于复杂环境介质中OPEs样品的前处理较为困难,方法有待改善;气相色谱-质谱联用(GC-MS)和气相色谱-氮磷检测器(GC-NPD)对弱极性和易挥发的OPEs分析效果好,而强极性和难挥发的OPEs多用液相色谱-质谱联用(LCMS);气相色谱-质谱串联(GC-MS/MS)、液相色谱-质谱串联(LC-MS/MS)和高效液相色谱-质谱串联(UPLC-MS/MS)等对多种复杂的环境介质中的OPEs均有较好的检测分析效果,但并未普及。最后,对OPEs分析测试方法的发展趋势提出了展望。     

Evaluation of linear alkylbenzenesulfonate (LAS) biodegradability in sediment by solid‐phase extraction and HPLC analysis

The linear alkylbenzenesulfonate (LAS) sorption on environmental sediments has been known long ago. Their high concentrations reflect the massive input of these chemicals from household and industrial uses. However few attempts were made to identify biodegradation metabolites of LAS in sediment. In this report, a method for the determination of these compounds in sediment samples by high‐performance liquid chromatography (HPLC) is described. The first step of our work was performed by solid‐phase extraction with octadecyl‐bonded silica (C18) mini‐columns and provided a suitable recovery of LAS (90 ± 5%) and most metabolites. Furthermore, laboratory investigations led to study the behaviour of LAS in sediment. The environmental samples used for this purpose were collected from a pond (named étang de Bolmon) located in the French Mediterranean coast. Our results were in agreement with an aerobic biodegradation process of LAS that occurred only with high values of sediment redox potential and needed the samples to be vigorously shaken to ensure adequate mixing and suspension of particulate material. In a stagnant sediment or under anaerobic conditions, LAS is not degraded. p‐Sulfophenylacetic acid and p‐sulfocinnamic acid were evidenced as predominant metabolites and were found not to be persistent.     

A novel extraction method for analysing available sulfamethoxazole in soil

A novel extraction method was established to determine the water-extractable (available) content of sulfamethoxazole (SMX) in soil. The SMX imprinted polymers (MIPs) were synthesised and the performance was evaluated by Fourier transform infrared spectroscopy, scanning electron microscopy and binding experiments. Results showed that the MIPs exhibited good selectivity for SMX, so the MIPs were applied as a sorbent. SMX in soil was extracted by water, sorbed from the extract to MIPs and analysed with a high performance liquid chromatography (HPLC) after its desorption from MIPs. Meanwhile, the classic organic solvent extraction was employed to measure the total SMX content in soil. Results showed that when SMX level in spiked soils varying from 1.0–500?μg?kg^?1, the observed recoveries of available SMX contents ranged from 63.27?±?3.11% to 82.11?±?2.77% (n?=?3), while the total SMX varied between 89.59?±?1.65% and 97.64?±?3.92% (n?=?3). The detection limit of the developed method for SMX in soils was 0.05?μg?kg^?1. Available SMX contents in five field soil samples ranged from 0.13 to 4.14?μg?kg^?1, which were only 0.35–25.40% of the respective total SMX contents. Results from this study manifest the importance of the extents of SMX immobilisation with different soils for assessing SMX's ecological and human health risks.     

Metalaxyl—its persistence and metabolism in soil

Different biotic and abiotic factors were found to play a vital role in attenuating metalaxyl residues in soil. In addition to metalaxyl many other products were found by HPLC and GC‐MS analysis while studying its soil metabolism in presence of natural sunlight. Three compounds were identified and characterized: 2,6‐dimethylaniline, 2,6‐dimethyl‐N‐ethylacetanilide and N‐(2,6‐dimethyl phenyl) alanine methyl ester.     

Cleanup by solid‐phase extraction and HPLC of organochlorine insecticides and PCBS in various nonfatty and fatty samples

An accurate, simple and cheap extraction and cleanup procedure for capillary GC analysis of organo‐chlorine insecticides (OCs) in vegetables (cabbage and carrots) at the ng/g level, and for soil at the μg/g level is presented. The cleanup is carried out on solid‐phase extraction (SPE) cartridges, filled with 500 mg silica, 1 g of deactivated Florisil (10% w/w water), and 100 mg of anhydrous sodium sulphate. Recoveries >90% are obtained. The cleanup of OCs in fatty samples on an HPLC LiChrosorb Si 100 column is evaluated for subsequent capillary GC analysis. Fractionation of OCs and Aroclor 1254 and 1260 on an HPLC Nucleosil 100 column appears to be satisfactory.     

Hydrolytic biodegradation of chlorothalonil in the soil and in cabbage crops

Broccoli and Chinese cabbage crops were treated at planting by pouring an emulsion of the fungicide chlorothalonil around the stem of the plant. During culture, chlorothalonil was biodegraded in soil into l,3‐dicarbamoyl‐2,4,5,6‐tetrachlorobenzene (compound 1), l,3‐dicyano‐4‐hydroxy‐2,5,6‐trichlorobenzene (compound 2), and l‐carbamoyl‐3‐cyano‐4‐hydroxy‐2,5,6‐trichlorobenzene (compound 3). Compounds 1 and 2 were the major metabolites in soil. In the harvested broccoli (in the flower) and Chinese cabbages (the leaves), the concentrations of chlorothalonil and of compounds 1 and 2 were lower respectively than 0.1, 0.1 and 0.5mg/kg fresh weight.     

Effect of MS-222 on response to light and rate of metabolism of the little skate Raja erinacea

The effect of tricaine methanesulfonate (MS-222) on the standard (SMR) and routine (RMR) metabolic rates of Raja erinacea was estimated from oxygen-consumption measurements. Data were gathered from a computerized, flow-through respirometry system. Individual trials were run for 96 h at 10 °C on anesthetized and untreated fish. The resulting rates, SMR = 20.1 ± 1.99 SE and RMR = 48.3± 2.5 SE mg O₂ kg⁻¹ h⁻¹, for an unanesthetized skate of 0.5 kg standardized weight, are the lowest reported for any elasmobranch. Periodogram analysis revealed a significant light-response component to the oxygen consumption of these fish, indicating a pattern of nocturnal and crepuscular activity. This activity pattern was disrupted in skates subjected to anesthesia. The use of low-dosage MS-222 in conjunction with the respirometry trials provides positive preliminary evidence that this technique may be useful in giving quick, accurate estimates of SMR in the more intractable elasmobranch fishes. Received: 15 January 1997 / Accepted: 6 February 1997     

Extracellular polymeric substances (EPS) from cyanobacterial mats: characterisation and isolation method optimisation

Extracellular polymeric substances (EPS) play an important role in bacterial mat formation and sediment stabilisation of coastal zones. The analysis of these secretion products on a molecular level is a prerequisite to understand their formation mechanisms and ecological function in microbial consortia. The present study focuses on the optimisation of EPS isolation and characterisation from cohesive cyanobacterial mats. Extracted EPS were analysed for quantity, content of total organic carbon and nitrogen, and bulk contents of neutral sugars, uronic acids, and proteins. These criteria are strongly influenced by the extraction conditions applied and therefore, the effects of different extraction media (NaCl or artificial seawater), addition of EDTA, centrifugal force, and purification via repeated ethanol precipitation on extraction success were determined. From this an optimised extraction procedure for EPS resulted. When using fresh mat samples, the yield of EPS amounted to 3.3 ± 0.8 mg g⁻¹ mat (dw). The isolated EPS were composed of nearly equal amounts of proteins and uronic acids (12.7 ± 1.5 and 11.8 ± 1.1%, respectively) and the bulk content of neutral sugars was 30.5 ± 2.6%. High contents of TOC and TN indicated relatively pure EPS and only a low contribution of inorganic compounds. Furthermore, low contents of 2-keto-3-deoxyoctonate and the small protein/polysaccharide-ratio in the EPS extracted by our method, signified low contaminations by intracellular polymers and hence a low rupture of cells. Our method provides an useful tool to evaluate further investigations of the composition, characteristics and properties of EPS on a sound basis.     

Solvent effects on quantitative analysis of brominated flame retardants with Soxhlet extraction

Reliable quantifications of brominated flame retardants (BFRs) not only ensure compliance with laws and regulations on the use of BFRs in commercial products, but also is key for accurate risk assessments of BFRs. Acetone is a common solvent widely used in the analytical procedure of BFRs, but our recent study found that acetone can react with some BFRs. It is highly likely that such reactions can negatively affect the quantifications of BFRs in environmental samples. In this study, the effects of acetone on the extraction yields of three representative BFRs [i.e., decabrominated diphenyl ether (decaBDE), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA)] were evaluated in the Soxhlet extraction (SE) system. The results showed that acetone-based SE procedure had no measureable effect for the recovery efficiencies of decaBDE but could substantially lower the extraction yields for both TBBPA and HBCD. After 24 h of extraction, the recovery efficiencies of TBBPA and HBCD by SE were 93 and 78% with acetone, 47 and 70% with 3:1 acetone:n-hexane, and 82 and 94% with 1:1 acetone:n-hexane, respectively. After 72 h of extraction, the extraction efficiencies of TBBPA and HBCD decreased to 68 and 55% with acetone, 0 and 5% with 3:1 acetone/n-hexane mixtures, and 0 and 13% with 1:1 acetone/n-hexane mixtures, respectively. The study suggested that the use of acetone alone or acetone-based mixtures should be restricted in the quantitative analysis of HBCD and TBBPA. We further evaluated nine alternative solvents for the extraction of the three BFRs. The result showed that diethyl ether might be reactive with HBCD and may not be considered as the alternative to acetone used solvents for the extraction of HBCD.     

土壤和沉积物中的聚合有机质对多环芳烃分布和提取的影响

为了研究土壤和沉积物中凝聚型有机碳(碳黑、干酪根)的含量及其对多环芳烃(PAHs)分布和提取的影响,分别用三氟醋酸(TFA)和在375℃下通氧燃烧的方法从珠江三角洲2个污染土壤和5个河口沉积物样品中提取酸非水解有机碳(NHC)和碳黑(BC);用索氏抽提法和不同溶剂的加速溶剂萃取法(包括连续加速萃取法ASESum和标准溶剂萃取法ASESTD)抽提土壤和沉积物中的多环芳烃,并在不同温度梯度(25℃到150℃)下用水为溶剂加速溶剂萃取其水溶态.结果表明,1)NHC是珠江三角洲土壤和沉积物中总有机碳的重要组成部分,NHC碳明显高于BC碳,NHC和BC分别占土壤和沉积物中有机碳的25.6%￣73.8%和4.64%￣17.3%.2)3种有机溶剂(丙酮、甲苯1、甲苯2)连续抽提的PAHs含量是索氏抽提的2.11倍;5种ASE方法(丙酮、甲苯1、甲苯2、ASESum、ASESTD)提取的PAHs含量与NHC含量存在明显的相关性,而且比PAHs含量与BC或无定型有机碳(AOC)含量的相关性更明显.3)在不同温度梯度下水溶态PAHs浓度符合Van’tHoff方程.研究说明除了BC外,非水解有机碳对土壤和沉积物中PAHs的分布和提取具有重要影响.     

加速溶剂萃取技术及其在环境分析中的应用

加速溶剂萃取技术是一项新颖的样品前处理技术，通过升高温度与压力结合使用有机溶剂，可快速，有效地由基体中萃取各种欲测物。本文系统地阐述了该技术的基本原理，各种影响因子及其在环境分析中的应用。该法适用于固体和半固体样品的前处理。     

Utilization of a new bdelloid rotifer (Philodina acuticornis odiosa) assay to evaluate the effect of salinity on the toxicity of chlorothalonil

Acute (24 h) toxicity tests were conducted to determine the toxicity of the fungicide chlorothalonil towards the freshwater bdelloid rotifer (Philodina acuticornis odiosa). Since rotifers are the dominant zooplankton species in many inland freshwater lakes in Australia, the influence of salinity on chlorothalonil toxicty was also assessed. The rotifers used in this study appeared to be reasonably tolerant to changes in salinity, with little mortality observed at 3760 µS cm^?1, increasing thereafter at higher salinity. The bdelloid rotifers were, however, found to be highly sensitive to chlorothalonil (24 h LC50, 3.2 µg L^?1) with results also suggesting that as salinity increases, so does toxicity (e.g., 24 h LC50 at 5000 µS cm^?1, 0.5 µg L^?1).     

Fecundity of the Barents Sea capelin (Mallotus villosus)

The fecundity and oocyte diameter of 70 female capelin (Mallotus villosus) from the Barents Sea were investigated. The average fecundity (±SE) was 11 542 (±261). Oocyte diameter and fecundity increased with increasing weight and length of the capelin. Interannual variation in capelin fecundity is large, and corresponds to differences in body weight as revealed by a comparison with previous studies. Received: 10 May 1997 / Accepted: 1 August 1997     

Kinetics of acetyl CoA: Arylamine N‐acetyltransferase from rapid and slow acetylator fish tissues

N‐acetyltransferase (NAT) activity was determined in 100 fish (Oreochromis mossambicus) livers using 2‐aminofluorene and p‐aminobenzoic acid as substrates. Overall, the liver NAT activity of the 50 females was higher than the liver NAT activity of the 50 males. The activities (mean ± SD) of NAT from kidney, blood, intestine, and liver of males was 0.42 ± 0.11, 0.12 ± 0.03, 0.12 ± 0.08, and 1.56 ± 0.54 nmol/min/mg protein for the acetylation of 2‐aminofluorene and 0.36 ± 0.09, 0.09 ± 0.01, 0.11 ± 0.04, and 0.46 ± 0.15 nmol/min/mg protein for the acetylation of p‐aminobenzoic acid. In kidney, blood, intestine, and liver from female fish, the activities obtained were 1.60 ± 0.12, 0.35 ± 0.07, 0.15 ± 0.09, and 1.89 ± 0.50 nmol/min/mg protein for 2‐aminofluorene and 0.95 ± 0.11, 0.27 ± 0.03, 0.13 ± 0.09, and 0.57 ± 0.12nmol/min/mg protein for p‐aminobenzoic acid. Kinetic constants for arylamine N‐acetyltransferase activity in kidney, blood, intestine, and liver from fish with rapid, intermediate, and slow acetylator activity were determined. Apparent K _m and V _max values for 2‐aminofluorene were 5.5 and 7‐fold higher for liver than for the other tissues. Apparent K _m and V _max values for p‐aminobenzoic acid were 3.5 and 4.7‐fold higher for liver than for the other tissues. Based on the 2‐aminofluorene NAT activity of liver, there appears to be a polymorphism in NAT activity with 16 rapid, 28 intermediate, and 56 slow acetylators among the 100 fish assayed. This is the first demonstration of acetyl CoA: arylamine N‐acetyltransferase activity in fresh water fish and could lead to the development of a fish model for monitoring the effect of pollution of water environments on native species.     

全氟辛酸对大鼠海马细胞内钙离子浓度的影响

采用连续灌胃染毒的方法,探讨了全氟辛酸(Perfluorooctanoic acid,PFOA)经口急性染毒对大鼠海马细胞内钙离子浓度的影响.选择雄性Wistar大鼠40只,实验组PFOA染毒剂量分别为2、8、30mg·kg-1(bw).连续灌胃染毒7天后,制备海马单细胞悬液,采用Fura-2/AM荧光探针法测定海马细胞内游离钙离子浓度([Ca2+]i),使用固相萃取-高效液相色谱/质谱联机法(HPLC/MS-MIS)检测血清与脑组织中PFOA浓度.结果表明,染毒组大鼠血清与脑中PFOA浓度均显著高于对照组水平(p<0.01),血清与脑中PFOA浓度之间存在显著的正相关关系(r2=0.611,p<0.01).PFOA染毒8、30mg·kg-1(bw)实验组海马细胞[Ca2+]i分别为(207.89±22.84)nmol·L-1和(284.19±14.75)nmol·L-1,显著高于对照组((141.68±11.47)nmol·L-1)和PFOA染毒2mg·kg-1(bw)实验组((147.38±19.23)nmol·L-1)(p<0.01).大鼠脑、血清中PFOA浓度分别与海马[Ca2+]i存在正相关关系(r2=0.552,p<0.01;r2=0.756,p<0.01).研究结果显示,PFOA暴露可使血清和脑组织中PFOA浓度增加,引起大鼠海马神经元细胞[Ca2+]i升高.     

加速溶剂萃取-固相萃取净化-超高效液相色谱串联质谱法测定土壤中11种全氟化合物

采用超高效液相色谱-串联质谱联用法（UPLC-ESI-MS/MS）,建立了分析土壤中11种全氟化合物（PFCs）的方法.以甲醇作为萃取剂,样品经加速溶剂萃取仪（ASE）萃取,固相萃取净化后,使用UPLC-ESI-MS/MS联用仪分析样品中11种PFCs.在6 min内就可快速稳定地将所选取的11种全氟化合物分离,且最低检测浓度为0.518—3.520 pg.g-1之间,这些化合物在土壤中的平均添加回收率在71.2%—119.2%之间.应用此方法测得宜兴市水稻土样品中所选取的PFCs含量为0.006—0.780 ng.g-1之间.     

Analysis,accumulation and central effects of trihalomethanes. I. bromoform†

The paper presents the results obtained in a study on the effects of organic micropollutants on the central nervous system of the rat, used herein as a suitable model for neurotoxicologic work. Bromoform, a member of the trihalomethane (THM) family, was the pollutant selected since it becomes a characteristic marker in the Barcelona potable water supply.

Analytical data on the GC‐ECD separation of THMs from other volatile halocarbons is presented. A mixed packed column 10% SE‐30/PEG 20M (94:6) at 70°C provides an adequate separation. The distribution of bromoform in rat plasma and tissues showed an accumulation in brain, kidney and fat, increasing in this order and a rapid elimination after 30 min. The effect on the central aminergic metabolism is studied by HPLC. The increased metabolic activity detected could be attributed either to an increased nervous activity, stimulating the metabolism of serotonin, or to its greater degradation.     

Aerobic metabolic rates of swimming juvenile mako sharks, <Emphasis Type="Italic">Isurus oxyrinchus</Emphasis>

The shortfin mako shark, Isurus oxyrinchus, is a highly streamlined epipelagic predator that has several anatomical and physiological specializations hypothesized to increase aerobic swimming performance. A large swim-tunnel respirometer was used to measure oxygen consumption (MO₂) in juvenile mako sharks (swimming under controlled temperature and flow conditions) to test the hypothesis that the mako shark has an elevated maintenance metabolism when compared to other sharks of similar size swimming at the same water temperature. Specimen collections were conducted off the coast of southern California, USA (32.94°N and 117.37°W) in 2001-2002 at sea-surface temperatures of 16.0–21.0°C. Swimming MO₂ and tail beat frequency (TBF) were measured for nine mako sharks [77–107 cm in total length (TL) and 4.4 to 9.5 kg body mass] at speeds from 28 to 54 cm s⁻¹ (0.27–0.65 TL s⁻¹) and water temperatures of 16.5–19.5°C. Standard metabolic rate (SMR) was estimated from the extrapolation to 0-velocity of the linear regression through the LogMO₂ and swimming speed data. The estimated LogSMR (±SE) for the pooled data was 2.0937 ± 0.058 or 124 mg O₂ kg⁻¹ h⁻¹. The routine metabolic rate (RMR) calculated from seventeen MO₂ measurements from all specimens, at all test speeds was (mean ± SE) 344 ± 22 mg O₂ kg⁻¹h⁻¹ at 0.44 ± 0.03 TL s⁻¹. The maximum metabolic rate (MMR) measured for any one shark in this study was 541 mg O₂ kg⁻¹h⁻¹ at 54 cm s⁻¹ (0.65 TL s⁻¹). The mean (±SE) TBF for 39 observations of steady swimming at all test speeds was 1.00 ± 0.01 Hz, which agrees with field observations of 1.03 ± 0.03 Hz in four undisturbed free-swimming mako sharks observed during the same time period. These findings suggest that the estimate of SMR for juvenile makos is comparable to that recorded for other similar-sized, ram-ventilating shark species (when corrected for differences in experimental temperature). However, the mako RMR and MMR are apparently among the highest measured for any shark species.     

Rapid liquid chromatographic analysis of Metoclopramide in pharmaceutical preparations

A sensitive, accurate and reproducible method for the analysis of metoclopramide, a gastrointestinal drug, has been described. An isocratic HPLC elution method was employed which requires about 10 minutes to be performed. The concentration of metoclopramide hydrochloride preparations was found to be 95.1 ±0.3% and 94.21 ±0.25% in tablet and injection formulations, respectively.