Composite Material that Comprised Metal–Organic Nanotubes and a Sponge as a High‐Performance Adsorbent for the Extraction of Pharmaceuticals and Personal Care Products from Environmental Water Samples

A composite material that comprised metal–organic nanotubes (MONTs) and a sponge, Cu?MONTs?sponge, was synthesized by using a rapid and convenient surfactant‐assisted dip‐coating method and used as a high‐performance adsorbent for the solid‐phase extraction of pharmaceuticals and personal care products (PPCP) from environmental water samples. By adjusting the surfactant concentration, a composite material that contained metal–organic nanotubes and a macroporous 3D porous sponge was constructed. This modified sponge achieved outstanding reproducibility as an adsorbent, with the adsorption of trace or ultratrace amounts of contaminants. Moreover, this composite material was conveniently recycled and its extraction efficiency only decreased by 6.3–12.1 % after 30 adsorption/desorption cycles. The resulting composite exhibited excellent adsorption capacity for PPCPs, which was attributed to its unique porous structure, natural hydrophobicity, and electrostatic interactions between the metal–organic nanotubes and analyte molecules. This Cu?MONTs?sponge material is an ideal adsorbent for the extraction of trace amounts of PPCPs from environmental water samples.     

Metal–organic framework based in‐syringe solid‐phase extraction for the on‐site sampling of polycyclic aromatic hydrocarbons from environmental water samples

In‐syringe solid‐phase extraction is a promising sample pretreatment method for the on‐site sampling of water samples because of its outstanding advantages of portability, simple operation, short extraction time, and low cost. In this work, a novel in‐syringe solid‐phase extraction device using metal–organic frameworks as the adsorbent was fabricated for the on‐site sampling of polycyclic aromatic hydrocarbons from environmental waters. Trace polycyclic aromatic hydrocarbons were effectively extracted through the self‐made device followed by gas chromatography with mass spectrometry analysis. Owing to the excellent adsorption performance of metal–organic frameworks, the analytes could be completely adsorbed during one adsorption cycle, thus effectively shortening the extraction time. Moreover, the adsorbed analytes could remain stable on the device for at least 7 days, revealing the potential of the self‐made device for on‐site sampling of degradable compounds in remote regions. The limit of detection ranged from 0.20 to 1.9 ng/L under the optimum conditions. Satisfactory recoveries varying from 84.4 to 104.5% and relative standard deviations below 9.7% were obtained in real samples analysis. The results of this study promote the application of metal–organic frameworks in sample preparation and demonstrate the great potential of in‐syringe solid‐phase extraction for the on‐site sampling of trace contaminants in environmental waters.     

A comparison of the critical parameters of some adsorbents employed in trapping and thermal desorption of organic pollutants

Summary A comparison of some adsorbents, commonly used for trapping trace volatile organic pollutants followed by thermal desorption, is presented. The evaluation has been performed on 12 compounds representative of the main classes of organic substances. Breakthrough volumes and desorption recoveries have been measured. Every adsorbent gave good results for a range of compounds, but none were able to cover all the compounds examined. Thus, a multilayer trap utilising the best features of each adsorbent was introduced with very good results.     

离线超临界流体萃取和气相色谱-红外-质谱联用测定水中有机污染物

利用吸附剂ＧＤＸ－３０１对黄河水中的有机污染物富集并以超临界ＣＯ２脱附后,通过气相色谱、色谱－红外－质谱联用技术对各目标分析物逐一定性,并比较了超临界ＣＯ２萃取和溶剂洗脱的结果。实验表明,在２０ＭＰａ,６０℃,４０ｍｉｎ条件下进行超临界ＣＯ２萃取时的萃取效率和溶剂萃取效率相当或略高。     

碳素基体固相微萃取吸附质的研制

研制了石墨型碳素基体固相微萃取吸附质,并以该新型固相微萃取装置联用气相色谱 电子捕获检测器分析水体中的有机农药。考察了吸附萃取时间及离子强度对分析结果的影响,并与商品装置进行了对比,结果表明其具有很好的应用前景。     

Recent trends in the liquid chromatography–mass spectrometry analysis of organic contaminants in environmental samples

An overview of liquid chromatography–mass spectrometry methods used for the determination of trace organic contaminants in environmental samples is presented. Among the organic contaminants the focus is given on five groups of emerging contaminants that raised most concern as environmental contaminants and therefore attracted attention of a research community: pharmaceuticals, drugs of abuse, polar pesticides, perfluorinated compounds and nanoparticles. Various aspects of current LC–MS methodology, using tandem and hybrid MS instruments, including sample preparation, are discussed.     

High resolution capillary GC–MS analysis of low molecular weight organic compounds in municipal wastewater

High resolution capillary gas chromatography–mass spectrometry has been used in combination with various sample preparation methods to analyze a wide range of low molecular weight organic contaminants in municipal wastewaters. Volatile organic compounds were extracted using a purge and trap concentrator connected directly to a wide bore DB-624 capillary column. Because of the high organic load in wastewater samples, this method was preferred to the more sensitive closed loop stripping technique which suffered from competition effects and insufficient adsorbent capacity. Volatile and semi-volatile base/neutral compounds and acids were extracted with dichloromethane at pH 11 and pH 2, respectively, or were recovered using a simultaneous distillation-extraction procedure. Acidic compounds were subsequently derivatized using diazomethane methylation. Both fractions were separated with a 30m DB-5ms capillary column. Specific ionic substances (LAS, NTA, EDTA) were isolated by solid-phase extraction then derivatized with diazomethane (LAS) or acetyl chloride in n-butanol (NTA, EDTA) before GC–MS analysis. This array of techniques enabled the identification of more than 150 organic contaminants in the influent of a municipal wastewater treatment plant in northern suburban Paris. The individual concentrations of these contaminants ranged from < 0.1 μg/l to 5.7 mg/l.     

Polyethyleneimine-grafted polyphosphazene microspheres for rapid and efficient capture of anionic dyes from wastewater

Developing novel adsorbent to capture organic contaminants from wastewater rapidly and efficiently is highly desirable for waste treatment and environmental restoration. Herein, we reported a new amino-rich spherical adsorbent (PZS-PEI) for highly-efficient uptake of anionic dyes from aqueous solution. The PZS-PEI adsorbent was fabricated through a two-step process including synthesis of PZS-Cl microspheres via room temperature polymerization of hexachlorocyclotriphosphazene with bis(4-hydroxyphenyl) sulfone and subsequent surface grafting reaction of PZS-Cl microspheres using branched polyethyleneimine (PEI). The microstructure of as-obtained PZS-PEI microspheres was fully characterized by scanning electron microscopy, Fourier transform infrared, X-ray photoelectron spectroscopy, zeta potential, and N₂ adsorption test. The adsorption performance of the PZS-PEI microspheres towards organic dyes was evaluated through carrying out a series of studies including various influence factor analysis, adsorption isotherm, kinetics, and thermodynamics. Results show that the PZS-PEI adsorbent owned good adsorption selectivity towards anionic dyes, and the maximum adsorption capacities for methyl orange (MO), acid chrome blue K, eosin-Y reached 190.29, 152.90, and 92.34 mg/g at 25 °C, respectively. In addition, the uptake behavior of organic dye by the PZS-PEI adsorbent conformed to Freundlich isotherm and pseudo-second order kinetic model, and the adsorption process followed a three-stage intraparticle diffusion mode with an endothermic and spontaneous characteristic. Electrostatic interaction and hydrogen bonding were responsible for the highly-efficient adsorption of the PZS-PEI adsorbent towards typical anionic dye MO.     

The automated determination of volatile organic contaminants in ambient air and/or soil gas by gas chromatography with selective detectors

Two systems have been developed which are suitable for the determination of sub parts per billion levels of organic contaminants in ambient air and soil gas. Gas samples are passed through an adsorbent where the contaminants are trapped. Following thermal desorption the contaminants are quantitated by capillary GC employing photoionizations electrolytic conductivity, and electron capture detection. The performance of the systems is described in detail.     

Analytical Intercomparison Exercises and Harmonization within Environmental Laboratories from Developing Countries

Abstract

Since the early 60's, the IAEA implements a Quality Assurance (QA) programme for the Member States. As part of this programme, the IAEA organized more than 150 analytical intercomparison exercises and produced more than 70 Certified Reference Materials for a wide range of determinands, encompassing radionuclides, trace elements, petroleum hydrocarbons, pesticides and PCBs. From the IAEA — Marine Environment Laboratory in Monaco, analytical Quality Assurance services are provided for non-nuclear contaminants in marine materials.

Results of recently organized worldwide intercomparison exercises using the sample materials IAEA-142 (mussel tissue homogenate) and IAEA-140 (seaweed homogenate), show that some progress was achieved worldwide in the analyses of the more common environmental contaminants. However, results also show that difficulties in obtaining accurate data for trace elements and especially for organic contaminants are still widespread, particularly in developing countries. Therefore, the success of international cooperative programmes as well as of many regional environmental monitoring programmes, depends on improved quality and comparability of data which has to be achieved still through reinforced Quality Assurance programmes. To this aim, the IAEA/UNEP/IOC-UNESCO inter-agency programme on marine pollution promotes the adoption of Reference Methods for harmonization of techniques used in developing and developed countries, organizes frequent intercomparison exercises, and produces certified marine Reference Materials which are made available to laboratories worldwide.     

Artifact formation from the use of potassium-iodide-based ozone traps during atmospheric sampling of trace organic gases

Trace atmospheric gases have been sampled using potassium-iodide-based reactant traps for ozone removal. GC-MS analysis revealed the presence of organic iodine compounds which were present neither in the atmosphere nor as contaminants of the materials used, but more likely arose from reactions of organic gases or aerosols sampled with reactive iodine or hypoiodite released from reaction of ozone with potassium iodide in the traps. Losses of the individual organic trace gases measured were not, however, observed as a result of this mechanism. Several cautions in identifying unknown compounds from the atmosphere when using potassium iodide ozone traps are discussed.     

Usage of Date Stones as Adsorbents: A Review

In this article, the use of date stones (thrown as a waste material) as adsorbent for the removal of a variety of adsorbates in aqueous and gaseous streams have been reviewed. Adsorption plays a role in the wastewater treatment as a polishing process, especially on activated carbon at tertiary treatments. In this review, the preparation and characterization technique along with the applications of the date stones as adsorbent has been presented in detail. A comprehensive study and the comparison of the available data in literature reveal that the date stones can be used as a potential adsorbent for a wide variety of toxic contaminants such as dyes, heavy metals, insecticides, etc.     

Preparation and analysis of a marine sediment reference material for the determination of trace organic constituents

Summary A new marine sediment Standard Reference Material (SRM) has been prepared and analyzed for the determination of trace organic constituents. SRM 1941, Organics in Marine Sediment, has been certified for concentrations of 11 PAHs using results obtained from gas chromatography (GC) with flame ionization detection, gas chromatography-mass spectrometry, and liquid chromatography with fluorescence detection. Non-certified values for 24 additional PAHs are also reported. GC with electron capture detection was used to provide non-certified concentrations for 15 PCB congeners and 7 chlorinated pesticides. In addition to the organic contaminants, concentrations of 32 major and trace elements were determined using neutron activation analysis, and the sulfur content was also determined using isotope dilution thermal ionization mass spectrometry.     

Microwave-assisted micro-solid-phase extraction for analysis of tetracycline antibiotics in environmental samples

In this study, a novel solid-liquid-solid extraction approach, which was termed ‘microwave-assisted micro-solid-phase extraction’ (MAE-μ-SPE), was developed. Target analytes were extracted from the sample into extraction solvent enhanced by microwave field, following adsorption by the adsorbent in the micro-solid-phase extraction device. Without any clean-up steps, the extracts were analysed by high performance liquid chromatography coupled with ultra-violet detector. The MAE-μ-SPE approach was developed for the extraction of four tetracycline antibiotics residues in environmental soil, sludge and atmospheric particulate matters. Variables affecting extraction procedures were systematically investigated. Low detection limits of 0.1–6.3 ng/g and low quantification limits of 0.33–20.7 ng/g were achieved under optimised conditions. The recoveries of antibiotics ranged from 70.6% to 110.5% with relative standard deviation of less than 15.1%. The predominance was showed when compared to conventional MAE and μ-SPE method. According to the results, MAE-μ-SPE was proved to be a simple and effective sample preparation method for the analysis of trace organic contaminants in environmental samples.     

Multi-residue contaminants and pollutants analysis in saffron spice by stir bar sorptive extraction and gas chromatography-ion trap tandem mass spectrometry

A method for the simultaneous determination of 46 semi-volatile organic contaminants and pollutants in saffron has been developed for the first time using a stir bar sorptive extraction technique and thermal desorption in combination with gas chromatography-ion trap tandem mass spectrometry. The analytical method proposed was easy, rapid and sensitive and showed good linearity, accuracy, repeatability and reproducibility over the concentration range tested. Moreover, the correlation coefficients were higher than 0.98 for all target compounds and detection limits were lower than 1 microg/kg except for simazine. The present method was also applied for the analysis of trace contaminants in saffron samples.     

Aversatile β-cyclodextrin functionalized silver nanoparticle monolayer for capture of methyl orange from complex wastewater

The toxic organic dye contaminants in wastewater are extremely harmful to the ecosystem.Surface enhanced Raman scattering(SERS) is a technique with high sensitivity and chemical specificity which fulfills the requirements for monitoring dye contaminants in wastewater.However,as one of the common dye contaminants,methyl orange(MO) has very weak affinity to metallic surfaces and is difficult to be detected by SERS at low concentrations.Therefore,a new type of SERS substrate with Ag nanoparticle monolayer functionalized by mono-6-deoxy-6-thio-β-cyclodextrin(β-CD-SH) was prepared to efficiently capture and detect MO in wastewater with a limit of detection of 5×10^-7 mol/L.The hydrophobic cavity of β-CD is responsible for the efficient trap and enrichment of MO on the Ag NPs surface,achieving a strong SERS signal of MO at low concentrations and at different pH values.This study provides new insight into designing a well-performed adsorbent for the capture and detection of organic contaminants.     

Graphitic solid core carbon nanorods grown on silica sands using electron cyclotron resonance chemical vapor deposition as a highly efficient and green sorbent for removal of phenol derivatives from water sources

In this study, graphitic solid core carbon nanorods (GSCNRs) were, for the first time, anchored to the surface of silica sands through the electron cyclotron resonance chemical vapor deposition method to provide coated silica sands as a new, low-cost, green, and efficient adsorbent for the removal of organic pollutants such as phenol and 2,4-dichlorophenol (2,4-DCP) from aqueous mediums. The characteristics of GSCNRs/SiO₂ were confirmed through Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy techniques. After the optimization of several parameters, the removal efficiency of phenol and 2,4-DCP using 1 g of adsorbent amount, the initial concentration of pollutants (10 mg/L phenol and 15 mg/L 2,4-DCP), a contact time of 10 min (phenol) and 20 min (2,4-DCP), and pH = 7 were 69 and 89%, respectively. The adsorption isotherm models of Langmuir and Freundlich, as well as pseudo-first-order and pseudo-second-order kinetic models, were examined under optimal conditions. Eventually, GSCNRs/SiO₂ was regenerated five times for the removal of phenol and 2,4-DCP. The removal efficiency of the tested contaminants from inlet raw water of a water treatment plant using the proposed adsorbent was investigated.     

An overview of laboratory performance studies conducted by the IAEA for marine pollution studies of metals and organic contaminants

Aspects of the International Atomic Energy Agency (IAEA) Analytical Quality Control Services (AQCS) for marine environmental studies are discussed, focusing on recent laboratory performance studies (LPS) and the production of reference materials for trace metals and organic compounds in various marine matrices. The IAEA has organized seventeen global interlaboratory studies for a range of organic contaminants. Of note has been the inclusion of numerous polychlorinated biphenyl congeners (PCBs) and some sterols of anthropogenic origin. Concurrently, there have been eleven worldwide intercomparison exercises for trace metals in the marine environment, most of which included methylmercury. Although such interlaboratory studies can help improve performance in individual laboratories and regional laboratory networks, the results reveal that problems remain in the determination of some metals and many organic contaminants.     

DESORPTION OF VOCs FROM POLYMERIC ADSORBENTS UNDER MICROWAVE FIELD

1. INTRODUCTION Nowdays the volatile organic compounds (VOCs) have become important pollutants to air [1]. The source of these wastes is very wide. The leakage of the VOCs from chemical and pharmaceutical manufacturing, printing processes, paint and adhesive manufacturing and applications, composites and fiberglass molding etc. is the source of the pollutants. A number of adsorbents are capable of capturing a wide range of VOCs. However, the conventional process of regenerating …     

煤烟气中痕量有机物的分析及去除

采用不同吸附剂对煤烟气中的痕量有机物进行了富集，比较了各种吸附剂的富集能力，对富集的样品用索氏提取及超临界流体萃取装置进行了萃取，用ＧＣ－ＭＳ－ＤＳ联用方法作了定性鉴定，指出超临界萃取技术在提取煤烟气中痕量有机物方面的优势。探讨了用催化转化法去除煤烟气中有机污染物的可能性。