气相色谱法对茶园土壤中3种农药残留量的检测

通过对来自六种不同茶园土壤的三种农药残留量的监测,对茶园环境质量现状进行了较系统的调查,并进行了茶园的污染评价。本研究以丙酮为提取剂,样品经提取和浓缩后,采用毛细管柱气相色谱分离,电子捕获检测器(ECD)检测农药残留,外标法定量。不同种类茶园土壤的农药残留量是不同的。用气相色谱法分析茶园土壤中农药残留,全面了解茶园中拟除虫菊酯类农药残留量现状,有利于更好地采取行之有效的措施降低农药残留量,对促进茶叶的出口贸易也起到重要的作用。     

Multivariate Optimization of Binary Solvent Microextraction for the Simultaneous Determination of Endocrine Disruptive Phenolic Compounds and Organochlorine Pesticides in Wastewater and Sludge Samples by GC-MS

This study presents the development of a sensitive and accurate dispersive liquid-liquid microextraction method using binary solvents for the simultaneous determination of endocrine disruptive compounds by GC-MS. Optimum binary solvent and dispersive solvent amounts were determined using an experimental design. The main effects of these parameters and their interaction effects were assessed using analysis of variance. The detection limits of the analytes under optimal experimental conditions ranged between 0.16–1.5 ng/mL. All analytes exhibited good linearity over broad calibration ranges, and high precision (%RSD?<?8.0%) was obtained for six repeated readings of the lowest concentrations of the calibration plots. The method’s applicability and accuracy were tested on two municipal wastewater samples spiked at 10, 50, and 100 ng/mL. The recovery results obtained ranged between 82 and 108%, indicating that the method can be used to quantify the analytes in wastewater matrix with substantial accuracy. In addition, matrix matching calibration method was used to improve the percent recovery (≈?100%) for a waste sludge sample spiked at 50 ng/mL.     

Selective Determination of Chromium(VI) in Industrial Wastewater Samples by Micro-Electromembrane Extraction Combined with Electrothermal Atomic Absorption Spectrometry

This study describes application of free liquid membrane (FLM) in micro-electromembrane extraction (μ-EME) of Cr(VI) from wastewater samples. Amount of Cr(VI) was quantified by electrothermal atomic absorption spectrometry. The transportation of Cr(VI) across the FLM was explored by electrokinetic migration and ion-exchange process. FLM and acceptor solution types, pH of donor and acceptor solutions, applied electrical potential, as well as FLM thickness were optimized. Presence of an anion exchange carrier (methyl trialkyl-ammonium chloride, Aliquat 336) in FLM facilitated Cr(VI) transportation. The best performance was observed for 1-octanol (containing 5% Aliquat 336) with thickness of 1 mm used as FLM, under applied electrical potential of 75 V, when 0.5 M NaClO₄ and 0.1 M HCl were used as the acceptor and donor phases, respectively; and the extraction time was set to 5 min. Linearity was obtained in the working range of 0.5–14.0 ng mL^?1 Cr(VI) (R²?>?0.98). The calculated limit of detection was below 0.06 ng mL^?1. Application of this method to wastewater samples showed that relative recoveries of the spiked Cr(VI) in the samples were in the range of 73.8–85.1%, based on the standard addition method.     

3种水培观赏植物净化模拟污水的试验研究

利用观赏植物净化水体是目前湖泊、污染水体治理研究的热点。选取春羽、绿萝和铜钱草3种常见观赏植物作为水培试验研究对象,探讨这3种植物的水生栽培技术并用去除率指标研究其对模拟污水(劣V类)的净化效果。结果显示:春羽、绿萝、铜钱草对污染水体均具有较好的适应性及水体净化能力,对污染水体中总磷(TP)的去除率均达90%以上,净化效果很好;对总氮(TN)的去除率分别为64.6%,74.2%,65.1%,对氨态氮(NH3-N)和硝态氮(NO-3-N)的去除率分别为93.3%,96.3%,95%和90.7%,99.3%,47.1%,除铜钱草外,净化效果显著;对水体中化学需氧量(CODcr)的去除率分别为33.2%,49.8%,44.3%;去除率均大于无植物对照处理。此外,在水培植物的生长过程中,测定了植物的株长、叶数和鲜重,其中鲜重能较好地反映生长情况与污水处理效果,可以为水培观赏植物应用于湖泊等污染水体的生态修复治理工程提供参考。     

Treatment of Domestic Wastewater by Three Plant Species in Constructed Wetlands

Three common Appalachian plant species (Juncus effusus L., Scirpus validus L., and Typha latifolia L.) were planted into small-scale constructed wetlands receivingprimary treated wastewater. The experimental design includedtwo wetland gravel depths (45 and 60 cm) and five plantingtreatments (each species in monoculture, an equal mixture of the three species, and controls without vegetation), with two replicates per depth × planting combination. Inflow rates (19 L day^-1) and frequency (3 times day^-1) were designed to simulate full-scale constructed wetlands as currently used for domestic wastewater treatmentin West Virginia. Influent wastewater and the effluent from each wetland were sampled monthly for ten physical, chemical and biological parameters, and plant demographic measurements were made. After passing through these trough wetlands, the average of all treatments showed a 70% reduction in total suspended solids (TSS) and biochemical oxygen demand (BOD), 50 to 60% reduction in nitrogen (TKN), ammonia and phosphate, anda reduction of fecal coliforms by three orders of magnitude. Depth of gravel (45 or 60 cm) had little effect on wetland treatment ability, but did influence Typha and Scirpus growth patterns. Gravel alone provided significant wastewater treatment, but vegetation further improved many treatment efficiencies. Typha significantly out-performedJuncus and Scirpus both in growth and in effluent quality improvement. There was also some evidence that the species mixture out-performed species monocultures.Typhawas the superior competitor in mixtures, but a decline in Typha growth with distance from the influent pipe suggested that nutrients became limiting or toxicities may have developed.     

土壤中硝化抑制剂DMPP含量的气相色谱测定法

建立了一种检测土壤中吡唑类硝化抑制剂DMPP含量的气相色谱法。DMPP在NaOH溶液中可定量转化为DMP,从5种有机溶剂中选择氯仿作为DMP的萃取剂。本文采用吡啶做为内标物,内标校正因子fDMP和fDMPP分别为1.6775和3.3884。通过DB-1701气相色谱柱,氢火焰离子化检测器(FID)定量检测氯仿溶液萃取相中的DMP。本法添加回收率为97.4%～98.8%;RSD为0.70%～2.09%;土壤中DMPP的检出限为0.4mgkg-1。应用本法测定在潮棕壤中10℃、20℃和30℃时DMPP的降解半衰期分别为大于28d、14d和7d。     

气相色谱法测定水产品中三氯杀螨醇残留量

为拓展食品中农药残留监控范围,本文建立了水产品中三氯杀螨醇的气相色谱测定方法。试验基质为鳗鲡、罗非鱼、对虾、玻纹巴菲蛤,取其可食用组织的均匀试样1g,用正己烷超声萃取,用浓硫酸和弗罗里硅土净化,二氯甲烷／正己烷混合液淋洗层析柱。洗脱液收集和旋转蒸发浓缩后,用气相色谱法测定其中的三氯杀螨醇,外标法定量。测定仪器为HP6890N型气相色谱仪,配HP7683B型自动进样器、HP-5型毛细管气相色谱柱（30m×0．32mm×0．25μm）和。Ni微电子捕获检测器。三氯杀螨醇浓度线性范围是0．0025-0．4μg·mL-1（r=0．9998,P〈0．001）,方法定量检测下限为0．01μg·g-1。用未检出三氯杀螨醇的鳗鲡等4种试样,添加3个水平的三氯杀螨醇,分别为0．01、0．10、O．50μg·g-1,每种试样每个添加量测定6份。结果显示,加标回收率在71％-111％范围内,批内变异系数为3．2％～8．5％（n=6）,批间变异系数为2．5％～7．1％（n=4）。定量限点加标试样的回收率为73％～94％,批内变异系数为5．9％-7．7％,峰高信噪比〉10。本方法试样用量少,前处理简便,可操作性强,适合测定水产品可食部分的三氯杀螨醇残留量。     

Behavior of phenolic substances in the decaying process of plants: I. Identification and Quantitative Determination of Phenolic Acids in Rice Straw and Its Decayed Product by Gas Chromatography

Phenolic acids in rice straw and its decayed product were surveyed and quantitatively analyzed by gas chromatography.

1) Thirteen kinds of phenolic acids in rice straw and its decayed product were identified. Besides p-hydroxybenzoic, vanillic, P-coumaric, and ferulic acids which had been already reported, nine phenolic acids were newly identified; these were benzoic, salicylic, syringic, protocatechuic, β-resorcylic, caffeic, sinapic, gallic, and gentisic acids.

2) A gas chromatographic analysis was applied to the micro-determination of major phenolic acids in rice straw and . the decayed products. The methanolic alkaline extracts from them were washed with ether, acidified, transferred into ether, trimethylsilylated, and injected into a gas chromatograph equipped with a silicon SE-30 column. The recoveries of p-coumaric, p-hydroxybenzoic, vanillic, and syringic acids were more than 90%, and ferulic and syringic acids were recovered at about 70%.

3) The content of each of the above described major phenolic acids in rice straw ranged from 0.002 to 0.037% per dry weight. p-Coumaric acid was contained in the largest amount. Ferulic and vanillic acids followed. In the decayed straw, these contents decreased to 0.002–0.017%. The whole phenolic substances in ether-extracted fraction were present at 0.34%, and the amount decreased to one-third during the decaying process.     

3种挺水植物对生活污水主要污染物净化能力的研究

选用鸢尾(Iris tectorum)、石龙芮(Ranunculus sceleratus L.)、酸模(Rumex acetosa L.)3种挺水植物作为湿地植物进行无土栽培,研究它们在生活污水中的生长特性及对生活污水中主要污染物的净化能力。试验集中在春末夏初进行,结果表明,3种植物均生长良好。当污水停留时间(HRT)为7 d时,鸢尾对COD,TP,TN去除的贡献率分别为46.74%,17.71%,11.33%;石龙芮对COD,TP,TN去除的贡献率分别为39.82%,28.59%,8.88%;酸模对COD,TP,TN去除的贡献率分别为54.69%,20.26%,7.47%。经过处理后的污水水质显著提高,充分表明这3种植物应用于人工湿地是可行的。     

鲜猪肉中邻苯二甲酸二异辛酯含量的气相色谱检测方法初探

该文采用气相色谱仪对鲜猪肉中邻苯二甲酸二异辛酯(DEHP)的含量进行测定。采用提取、皂化工艺,使DEHP分解为邻苯二甲酸和异辛醇,用水蒸气蒸馏出异辛醇,萃取浓缩进样测定异辛醇的含量,并进一步换算出DEHP含量。结果显示：提取溶剂选用乙醚,提取时间6 h,皂化时间3h,在蒸馏液pH 7条件下,异辛醇萃取率为81.8％～88.0％,方法加标回收率为75.12％～84.95％,检出限为1.07×10^-3 mg/kg。该方法降低了对仪器设备的要求,为制定相关标准、保障食品与包装材料的安全提供了依据。     

径向流色谱分离纯化海藻多糖及其抗氧化活性比较分析

以裂片石莼、亨氏马尾藻和海萝3种海藻为原料,采用超声波辅助提取、分步醇沉得到7种组分粗多糖,利用径向流色谱分离纯化粗多糖,测定超氧阴离子、羟基自由基和ABTS 3种自由基体系下其抗氧化能力.结果表明:通过径向流处理,多糖回收率和蛋白脱除率分别可达97.79％和87.32％;7种海藻多糖组分均具有抗氧化活性,均随多糖浓度的增加而增加,马尾藻60％醇沉组分(SHP60)抗氧化活性最高,在其70μg·mL-1浓度时,对超氧阴离子自由基和羟基自由基清除率分别为74.34％和71.84％;同种海藻的中等分子量多糖组分的抗氧化活性较强.     

Comparison of Phosphorus Determination Methods by Ion Chromatography and Molybdenum Blue Methods

The suppressed ion chromatography (IC) and molybdenum blue methods were used to comparatively evaluate phosphorus (P) concentrations. Most of the P was more resistant to hydrolysis in ion chromatography as compared to the molybdenum blue method. However, P analysis by IC is more liable to be interfered than the molybdenum blue method because of the presence of high bivalent and trivalent metal ions. Polyvalent metal ions interfere with organic P hydrolysis or the release of P from colloids during P investigation, which leads to a difference of ortho-phosphate concentrations determined by IC and molybdenum blue methods. During the environmental samples analysis, the ortho-phosphate obtained by the IC method was usually less than that obtained by the molybdenum blue method.     

亚麻籽中酚酸化合物的鉴定与含量测定

为了揭示亚麻籽中酚酸类化合物的组成、形态及分布情况,采用反相高效液相色谱法-二极管阵列技术,对亚麻籽粉乙醇提取物的碱解、酶解产物进行鉴定与分析。结果表明,开环异落叶松树脂素酚二葡萄糖甙(SDG)、阿魏酸和对香豆酸以稳定的结合态存在于亚麻种子中;不同水解方法对酚酸化合物的释放量具有显著影响,高温(120℃)碱解条件下SDG的释出量最大;不同品种间各组成成分基本相同,但含量差异显著,其中SDG的质量分数为8~16.5mg·g~(-1),对香豆酸、阿魏酸的质量分数为0.3~1.35mg·g~(-1),阿魏酸与对香豆酸含量之间存在显著的相关性(R=0.89*)。本研究为亚麻籽酚酸资源开发过程中的原料选择、工艺确定、质量控制等环节提供了技术支持。     

Solventless Microextraction Techniques for Determination of Trihalomethanes by Gas Chromatography in Drinking Water

Three different solventless sample preparation techniques based on microextraction, membrane extraction, and headspace extraction have been developed and optimized for determination of trihalomethanes in drinking water by gas chromatography electron capture detector and mass spectrometry detection. The techniques employed were headspace (HS) solid-phase microextraction, hollow fiber liquid-phase microextraction (HFLPME) and HS extraction. All techniques used were optimized with different experimental designs in order to select the most relevant variables which significantly affect the different processes. The different analytical figures of merit such as limit of detection (LOD), limit of quantification, reproducibility, accuracy, and linear dynamic range were obtained. The new HFLPME method applied used a hollow fiber membrane of polypropylene and the optimized variables were extraction time, extraction temperature, and salting-out effect. The software MODDE 6.0 was used and its design was one central composite on face with a total of 17 runs. The best conditions for the HFLPME were 20 min, 40°C, and 10% NaCl, respectively. The LODs ranged from 0.018 μg·L⁻¹ (for CHClBr₂) to 0.049 μg·L⁻¹ (for CHBr₃), being this technique the most sensitive one among those studied. Finally, after having optimized the sample preparation techniques and chromatographic conditions, several water samples were taken in two different water treatment plants in Spain (Zaragoza) and Colombia (Viterbo, Caldas). The results obtained are shown and discussed.     

超声提取-离子色谱法测定土壤中10种水溶性阴离子

采用超声提取–离子色谱法测定了土壤中F~–、CN~–、BrO_3~–、Cl~–、NO_2~–、Br~–、NO_3~–、PO_4~(3–)、SO_4~(2–)、C_2O_4~(2–)等10种水溶性阴离子含量。样品中阴离子用水浸提,提取条件为:固液比1:10,温度30℃,超声振荡时间30 min。提取完成后离心,取上清液通过0.22μm滤膜过滤后测定。在选定的离子色谱测定条件下,10种被测阴离子的检出限为0.009 7～0.31 mg/kg,不同阴离子的加标回收率为84.0%～112%,相对标准偏差(n=7)为0.09%～4.3%。     

Effect of Treated Wastewater Irrigation on Plant Growth and Biological Activity in Three Soil Types

The effects of two types of treated wastewater on soil biological activity were studied in a pot experiment. Four irrigation treatments were tested on both soils sown with barley and unsown soils: distilled water (DW), half-strength Hoagland nutrient solution (NS), treated wastewater from a conventional treatment plant (CWW), and treated wastewater from a lagoon (LWW). Three types of soils were used: Chromic Luvisol, Calcaric Regosol, and Calcaric Arenosol. The greatest barley production was obtained under NS treatment in the three soils, whereas the least was produced by the DW treatment. Soil biological activity was strongly correlated to plant production, whereas no effect of treated wastewater irrigation was observed in the unsown soils. The greatest soil biological activity was found in the Luvisol. In conclusion, both soil type and the presence of plant root systems were found to have more influence on soil biological activity than irrigation water type.     

Simultaneous Determination of Low Molecular Weight Organic Acids in Soil Solution by Ion Chromatography

A simple and precise ion chromatographic (IC) method for determination of citric, malonic, succinic, formic, acetic and propionic acids in soil solution was developed. It requires a prior cleanup to the soil solution samples by anion exchange resin (AG1-X8) and determination of organic acids using a Dionex Model 2010i IC. Separation of organic acids by IC permitted their quantitation by conductivity measurements, following suppression of background conductivity by a fiber suppressor. A high degree of precision was achieved in the quantitation of organic acids studied. With the IC method, citric, malonic, succinic, formic, acetic and propionic acids can be determined simultaneously in 16 min. A single operator can analyze about 30 samples in a single working day.     

超声萃取–高效液相色谱测定土壤/沉积物中1-羟基芘

本文对超声萃取土壤/沉积物中1-羟基芘(1-hydroxypyrene)的提取条件进行了优化研究,建立了一种超声萃取–高效液相色谱–荧光检测1-羟基芘的方法。结果表明:甲醇和二氯甲烷的混合溶剂为最佳萃取溶剂;甲醇与二氯甲烷的体积比是影响萃取效率的主要因素。通过正交试验进一步确定了最佳提取条件为:甲醇/二氯甲烷体积比35∶65、土液比2 g∶10 ml、提取时间20 min、提取次数3次。在最佳提取条件下,5种不同类型的土壤/沉积物中1-羟基芘的加标回收率数值变化范围很大(6.6%~83.3%),并且这种变化与样品的pH密切相关,而与样品总有机碳含量无关。     

Quantitative Determination of Gluten Protein Types in Wheat Flour by Reversed-Phase High-Performance Liquid Chromatography

A combined extraction-HPLC procedure was developed on a microscale to determine the amounts of the different gluten protein types (ω5-, ω1,2-, α- and γ-gliadins; high molecular weight [HMW] and low molecular weight [LMW] glutenin subunits) in wheat flour. After preextraction of albumins and globulins from flour (100 mg) with a salt solution (2 × 1.0 mL), extraction of gliadins was achieved with 60% aqueous ethanol (3 × 0.5 mL). Subsequently, the glutenin subunits were extracted under nitrogen and at 60°C with 50% aqueous 1-propanol containing Tris-HCl (0.05 mol/L, pH 7.5), urea (2 mol/L) and dithioerythritol (1%). The separation and quantitative determination of gliadins and glutenin subunits was then performed by reversed-phase HPLC on C₈ silica gel at 50°C using a gradient of increasing acetonitrile concentration in the presence of 0.1% trifluoroacetic acid. The flow rate was 1.0 mL/min, and the detection wavelength was 210 nm. Temperature and flow rate were modified for the quantitation of single underivatized HMW subunits. To determine the absolute amounts of protein types, different protein standards (gliadin, LMW and HMW subunits, bovine serum albumin) with known protein contents were compared to HPLC absorbance areas. The calibration curves were almost identical and linear over a broad range (20–220 μg). This extraction-HPLC procedure allows an accurate, reproducible, sensitive, and relatively fast quantitative determination of all gluten protein types in wheat flour, and can be applied to quality evaluation of cereals as raw materials or in processed products.     

离子色谱法和毛细管电泳法测定土壤中氯离子、 硫酸根及其差异性

分别采用离子色谱法(IC)、毛细管电泳法(CE)两种仪器方法对不同pH土壤中Cl~–、SO_4~(2–)含量进行测定,并对其结果进行差异性分析。结果显示:参照标准物质的参考值(滴定法),IC与CE测定值的准确度、回收率均满足实验分析要求,但精密度差异较大,IC(RSD,3.61%)的稳定性优于CE(RSD,8.97%)。据差异性(F与t检验)分析,两种仪器方法测定酸性土壤中Cl~–、SO_4~(2–)含量存在显著性差异,而碱性、中性土壤的测定结果保持一致。对比4个被测样品基本性质发现,酸性土壤的pH与离子强度均低于其他样品,从而影响了石英毛细管的电渗流,最终改变了CE分离过程,这可能是Cl~–结果偏离的主要因素。同时,对于IC,酸性土壤较中性、碱性土壤更易由于离子交换效应产生次级保留(拖尾)。此外,采用碱性分离体系分离酸性样品易形成结晶,从而导致SO_4~(2–)含量的偏离。可见,两种方法各有优缺点。但是,IC较经典,而CE是一种新兴的仪器方法。测定像土壤这样基体较复杂的样品(特别是酸性土壤)中阴离子的仪器条件还需要进行更多摸索与优化,以促进这两种方法在土壤领域的推广与应用。