幼儿头发中微量元素含量与身高、体重关系研究

普查了４４９名１－６岁儿童头发中锌、铁、铜、钙、锰、铅含量,用分层聚类分析法对其身高、体重与各元素进行相关分析。幼儿身高与头发中锌含量呈相关关系,与头发中铅含量呈负相关关系。体重与头发中锌含量呈显著的正相关关系。与头发中铅含量呈负相关关系。说明锌有利于身体发育,而铅对身体发育不利。     

美国、日本和国产香烟中铅含量的比较

测定和比较了来自美国、日本和国产香烟的铅含量，结果表明，不同产地的烟中铅含量差别很大，并足以造成被动吸烟者血铅水平增高。     

应用同步辐射XRF分析胎毛中铅含量

通过同步辐射微束XRF分析了9名婴儿头发中的铅含量,结果表明,该法可了解胎儿在孕育期内体内铅含量的变化情况,甚至胎儿体内每天的铅含量的变化。通过分析铅在胎毛中含量的变化曲线,可以追踪孕妇在某段时期铅的接触史。     

加油站附近绿色植物中铅含量的测定

研究了HNO3，H2O2，HClO4体系中溶解绿色植物的最佳条件，在石墨炉原子分光光度计上测定了样液中的铅含量。发现距离加油站越近的地方绿色植物中的铅含量越高；在500m以外铅含量稳定，污染可以忽略不计。     

治疗脑血管疾病中成药中铅含量的测定及临床意义

采用原子吸收分光光度法测定了十种治疗脑血管疾病的中成药中铅含量。结果表明,十种中成药中铅含量有一定的差异。该结果为讨论铅元素与脑血管疾病中扣成药药效关系提供了有用的数据。     

玩具油漆涂层中总铅含量测定能力验证

我国是世界上最大的玩具生产国和出口国,近年来,出口玩具因安全问题不断遭到美国、欧盟的召回,其中,相当数量产品召回是因油漆涂层总铅含量超过美国CPSC 16 CFR 1303法规的规定。因此,加强玩具油漆涂层中总铅含量测定,对于保障玩具出口贸易,保护儿童身体健康等具有现实意义。为了解国内实验室对玩具油漆涂层中总铅含量检测的整体水平,识别和掌握实验室间存在的差异,提高玩具油漆涂层中总铅含量测定的检测水平。由     

成渝高速公路某段路旁土壤铅含量分布的研究

高速公路旁土壤铅污染主要来源之一为汽车尾气排放[1]。近年来,已经有不少文章报道了公路旁土壤铅含量分布规律[2-4],但大部分研究仅限于定性描述。为了定量研究公路旁土壤铅含量分布规律,已有报道在高斯烟源扩散模式基础上建立了路旁土壤中铅含量分布高斯方程[4-5],然而这几种     

铜质水嘴中铅含量与析出量的相关性探讨

试验探讨铜质水嘴中铅含量与析出量的关系。对一系列含铅标准铜片按照GB/T 17219–1998《生活饮用水输配水设备及防护材料的安全性评价标准》要求进行浸泡试验,使用原子吸收光谱法或电感耦合等离子体质谱法检测浸泡液中的铅含量,再利用20个已知铅含量的铜质水嘴样品进行析出量的检测和验证。得到铜质水嘴中铅含量与析出量的关系。试验结果表明:大部分内腔有电镀层的铜质水嘴,铅析出量小于5.0μg/L;内腔无电镀层的铜质水嘴中铅含量小于0.5%时,铅析出量小于5.0μg/L,符合GB/T 17219–1998标准要求。     

慢性支气管炎患者血清中铅含量的初步研究

采用原子吸收分光光谱法，测定了５０例慢性支气管炎患者血清中的铅含量。结果发现，慢性支气管炎患者血清中铅含量均高于正常参数值。从而给慢性支气管炎的治疗提供了一个新的研究探讨的途径。     

用X线荧光衍射法和原子吸收光谱法测定油漆中的铅含量

为勘查环境铅暴露的来源并评价其状况，应用K层X线荧光衍射法（XRF）对84张木制桌面表面油漆中的铅含量进行了测定。并应用原子吸收光谱法定量分析了8类18种液体油漆及12种内墙剥脱涂料中可溶性铅的含量。结果发现：所有桌面油漆的铅含量≤0．7mg／cm2，在正常范围内。但是，90年代以前生产的木质桌面表面油漆层中的铅含量明显高于90年代生产产品。液体油漆中铅含量为1．03×10－6～32800×10－6，其中超标者有3种，占16．7％，均为用于金属表面的防锈漆。内墙剥脱涂料中的铅含量为105×10－6～1430×10－6，均在正常范围内。结果提示：①应用便携式XFR检测桌面油漆中的铅含量，是一种快速、实用、准确的方法，非常有利于进行铅源的实地勘查；②除了少数几种工业用防锈漆以外，民用油漆，包括内墙涂料、家具、地板及桌面上用的油漆中的铅含量均未超标。但由于本调查未涉及80年代及更早时期的木质家具，老建筑中使用的油漆的铅污染情况如何，还有待进一步地勘查和研究。     

Evaluation of two methods for the extraction of antioxidants from medicinal plants

The efficiencies of two traditional extraction methods used in Chinese medicine (the decoction method and the maceration method) were evaluated for the extraction of antioxidants from medicinal plants. A group of medicinal plants possessing nutritious and tonic functions were chosen as model plants. A commonly used extraction method was used as a reference method. The antioxidant capacities and total phenolic contents of the extracts were measured by ferric-reducing antioxidant power and Trolox equivalent antioxidant capacity assays as well as the Folin–Ciocalteu method, respectively. The results obtained indicated that the two traditional extraction methods could effectively extract antioxidants from medicinal plants. These extraction methods can be applied to the analysis and purification of antioxidants in plants, respectively. At home, people can use these methods to extract antioxidants from plants for consumption. In the food industry, these methods could be utilized to prepare crude extracts from plants containing antioxidants for use as food additives. Figure Relation and comparison of extraction efficiencies of two traditional extraction methods with the reference method Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Dibenzotetraaza crown ethers: a new family of crown ethers based on o-phenylenediamine

Dibenzotetraaza (DBTA) crown ethers possess two o-phenylenediamine moieties. They are homologues of dibenzo crown ether phase-transfer catalysts and were prepared from the condensation of benzimidazoles with oligo(ethyleneglycol) dichlorides and oligo(ethyleneglycol) ditosylates. Compounds with ring sizes ranging from 18-crown-6 to 42-crown-14 were prepared. In addition, various altered benzimidizoles were used to produce DBTA crown ethers with modified substituents and ether bridges, as well as benzimidazolidine crown ethers. The synthetic approach presented here proved to be a convenient route to a new family of crown ethers with overall yields of up to 48% based on the benzimidazole. Yields for the ring-closing step were generally high, ranging from 51% to 94%, without the need for high-dilution conditions. Reaction of the DBTA crown ethers with alkyl and benzyl halides was found to be a facile way to obtain the corresponding tetra(N-organyl) compounds. Picrate extraction studies were carried out to determine phase-transfer catalytic capabilities. Extraction efficiencies for alkali-metal ions were lower than those for dibenzo-18-crown-6. Efficiencies were higher for other metal ions, with some selectivity for Pb(2+). Tetra(N-methyl) DBTA-18-crown-6 generally exhibited higher extraction efficiencies than its N-H analogue, but the selectivity was lower.     

Morphological and physiological responses of barley plants grown on soils characterised by metal toxicity and metal deficiency

Aim of this work was to investigate which are the effects on barley crops grown on two different soils: a soil lacking in Cu, an essential micronutrient (A) and a naturally polluted soil rich in lead, zinc, copper (B). In particular we investigated the relationship between some ecophysiological parameters such as biomass, chlorophyll concentration and guaiacolo peroxidase activity and the chemical-physical properties of the soils like pH, organic matter and heavy metal content. Because metals uptake by plants is strongly correlated with the bioavailable fraction rather then their total amount in a soil, we have measured also metal exchangeable forms, using a single extraction method (MgCl2 as extractant). Plants grown on soil B showed a metal content higher than background limits, whereas plants grown on soil A were characterised by a background Fe and Zn concentrations and by a tolerant Pb concentration. Conversely, Cu content in tissues of plants grown in soil A is found to be under the background limits. Copper-deficiency plants present chlorotic leaves followed by a reduced clorophyll content, while plants grown on metals contaminated soil showed an increase of peroxidase activity.     

Ultrasound and microwave-assisted extraction of metals from sediment: a comparison with the BCR procedure

In this paper we investigate alternatives to mechanical stirring for the extraction of the mobile fraction of metals from sediment, and analyze whether these techniques can reduce extraction time and improve reproducibility. We compare the quantities of metal extracted from BCR601 and BCR701 certified sediments using ultrasound bath, microwave-assisted extraction and the first step in the certified BCR sequential extraction procedure. Some environmentally important not-certified metals such as As, Mn, Co, Fe and Al have been included in this study. In the case of microwave-assisted extraction, we compare tests in which samples are exposed to constant, low power irradiation with tests using pulsed high power.

In the tests using the ultrasound bath, less metal was extracted than with the other extractive techniques and standard deviations were comparable to those obtained with the BCR procedure; in assays using microwaves at constant power, extraction efficiencies were different for different metals and for different reference materials and, in some cases, standard deviations were higher than those for the reference method. In contrast, tests with microwaves and constant temperature produced encouraging results: R.S.D.s lay in the 2–4% range, both for certified and not-certified metals; these values are very low compared to those for the reference method. Extraction efficiencies for certified metals were close to 100% for Cd, Zn, Cu and Ni and around 80% for Pb and Cr.     

Extraction and speciation of arsenic in plants grown on arsenic contaminated soils

A sequential arsenic extraction method was developed that yielded extraction efficiencies (EE) that were approximately double those using current methods for terrestrial plants. The method was applied to plants from two arsenic contaminated sites and showed potential for risk assessment studies. In the method, plants were extracted first by 1:1 water-methanol followed by 0.1 M hydrochloric (HCl) acid. Total arsenic in plant and soil samples collected from contaminated sites was mineralized by acid digestion and detected by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and hydride generation-atomic absorption spectrometry (HG-AAS). Arsenic speciation was done by high performance liquid chromatography coupled with HG-AAS (HPLC-HGAAS) and by HPLC coupled with ICP-mass spectrometry (HPLC-ICP-MS). Spike recovery experiments with arsenite (As(III)), arsenate (As(V)), methylarsonic acid (MA) and dimethylarsinic acid (DMA) showed stability of the species in the extraction processes. Speciation analysis by X-ray absorption near edge spectroscopy (XANES) demonstrated that no transformation of As(III) and As(V) occurred due to sample handling. Dilute HCl was efficient in extracting arsenic from plants; however, extraction and determination of organic species were difficult in this medium. Sequential extraction with 1:1 water-methanol followed by 0.1 M-HCl was most useful in extracting and speciating both organic and inorganic arsenic from plants. Trace amounts of MA and DMA in plants could be detected by HPLC-HGAAS aided by the process of separation and preconcentration of the sequential extraction method. Both organic and inorganic arsenic compounds could be detected simultaneously in synthetic gastric fluid extracts (GFE) but EEs by this method were lower than those of the sequential method. The developed sequential method was shown to be reliable and applicable to various terrestrial plants for arsenic extraction and speciation.     

Pressurized hot water extraction of bioactive or marker compounds in botanicals and medicinal plant materials

To reduce the use of organic solvent, pressurized hot water extraction (PHWE) has been shown to be a feasible option for the extraction of bioactive and marker compounds in botanicals and medicinal plants. The parameters that may affect the extraction efficiencies in PHWE include temperature, extraction time and addition of small percentage of organic solvent or surfactants. Currently, applications of PHWE for the extraction of thermally labile compounds in botanicals are still rather limited. PHWE with and without the additional of a small percentage of organic solvent such as ethanol is highly suited for the chemical standardization and quality control of medicinal plants. At the same time, it can be applied at the pilot scale as a manufacturing process for medicinal plants. Surfactant assisted PHWE was found to enhance the extraction of thermally labile and more hydrophobic species in medicinal plants at a lower temperature. The addition of small amount of surfactants in PHWE is highly suited for the determination of bioactive or marker compounds in medicinal plants. With proper optimization, PHWE was observed to have good extraction efficiency and precision when compared to other reference methods of extraction.     

HPLC-ICP-MS for a comparative study on the extraction approaches for arsenic speciation in terrestrial plant, Ceratophyllum demersum

For the determination of arsenic compounds in terrestrial plant samples, a crucial step is the efficient extraction of arsenic from the solid plant matrix. However, the use of methanol-water extraction often resulted in low extraction efficiencies of less than 50%. In this study, eight solid-liquid extraction procedures (mainly based on mechanical mixing and sonication) were evaluated for the recovery of arsenic species from a submerged freshwater plant, coontail (Ceratophyllum demersum), collected in Moira River, Ontario, Canada. Speciation of As in the extracts was carried out with both anion-, and cation-exchange HPLC with sector-field inductively coupled plasma mass spectrometric (SF-ICP-MS) detection. The results obtained depended critically on the extraction solvents used in different extraction procedures. Extraction with methanol-water led only to 9%–44% recoveries of As. A high extraction yield (approximately 82%) was obtained by water extraction. Alkaline hydrolysis also resulted in high extraction efficiencies (86%–98%), but severe oxidation of As(III) to As(V) was observed. A protease enzymatic extraction led to a recovery of 48%. Approximately 0.5% of the total As in the plant sample was lipid-soluble. It was found that the extraction of inorganic arsenic species was suppressed by the presence of methanol in the extraction solvents, while high content of methanol in the extraction solvents was effective for the extraction of organic arsenic species. Therefore, it is recommended to perform the extraction both with water alone and with methanol-water (9+1, v/v), in order to obtain the complete As species profile in terrestrial plants.     

超临界CO_2络合萃取绿茶中Cu、Pb和Cd的研究

本文采用超临界CO2络合萃取法萃取绿茶中的Cu、Pb和Cd。分别考察了不同改性剂和络合剂、萃取压力、萃取温度以及静态和动态萃取时间对三种重金属的萃取率影响。研究结果表明:以磷酸三丁酯(TBP)/HNO3为络合剂,乙醇为改性剂,在20MPa、333K、静态和动态萃取时间分别为30min的最佳条件下,Cu、Pb和Cd的萃取率分别为78.3%、73.2%和69.5%。     

226Ra, 210Pb, 210Bi and 210Po deposition and removal from surfaces and liquids

Deposition of ²²⁶Ra from water on nylon was investigated. Measurements performed for different pH and different radium concentrations in the water gave similar absolute activities deposited on the foil surface. Obtained results were used to estimate the amount of ²²⁶Ra plated-out on the nylon scintillator vessel in the solar neutrino experiment BOREXINO during filling of the detector. Another problem studied in the frame of BOREXINO was the removal of ²¹⁰Pb from its organic liquid scintillator by applying distillation and water extraction. After several tests had been performed for both methods it was found that after the water extraction the initial lead content in the scintillator sample was reduced only accordingly to the ratio of the volumes of the applied liquids (simple dilution). In contrast to this, distillation was very effective providing in the best case a ²¹⁰Pb reduction factor higher than 100. Removal efficiencies of the long-lived ²²²Rn daughters during etching from surfaces of standard and high purity germanium were investigated in the frame of the GERDA experiment, which aims to search for neutrino-less double beta decay of ⁷⁶Ge. The standard etching procedure of Canberra used during production of high purity n-type germanium diodes was applied to germanium discs, which had been exposed earlier to a strong ²²²Rn source for its progenies deposition. In contrast to copper and stainless steel, ²¹⁰Pb, ²¹⁰Bi and ²¹⁰Po was removed from germanium very efficiently. An evidence of a reverse process was also observed—the isotopes were transferred from the etchant to the clean germanium surface.     

Application of water as a solvent in microwave-assisted extraction for analysis of PCBs and CBzs in fly ash

Polychlorinated biphenyls (PCBs) and chlorobenzenes (CBzs) are two classes of dioxin precursors formed in municipal solid waste incinerators (MSWIs); they produce negative health effects similar to those of dioxins. Reducing the analytical time required for determining the concentrations of these compounds in MSWIs is important for quickly evaluating their importance and assessing associated health risks. In the present study, water is used as a safe and environmentally friendly solvent in microwave-assisted extraction (MAE) for PCB and CBz analyses. MAE is compared with traditional Soxhlet extraction (SE) to determine the extraction efficiencies. The evaluation of extraction efficiencies shows that MAE has a high extraction efficiency compared with that of SE when water content is lower than 60%. Furthermore, the extraction time and organic solvent consumption are reduced with MAE compared with SE.