Analytical-scale microwave-assisted extraction

A method based on pressurized fluid extraction (PFE) was developed for measuring microplastics in environmental samples This method can address some limitations of the current microplastic methods and provide laboratories with a simple analytical method for quantifying common microplastics in a range of environmental samples The method was initially developed by recovering 101% to 111% of spiked plastics on glass beads and was then applied to a composted municipal waste sample with spike recoveries ranging from 85% to 94% The results from municipal waste samples and soil samples collected from an industrial area demonstrated that the method is a promising alternative for determining the concentration and identity of microplastics in environmental samples

A Procedure for Measuring Microplastics using Pressurized Fluid Extraction.

The applications of ultrasound as auxiliary energy for accelerating leaching processes are reviewed to alert analysts to its advantages. The widely used batch systems are compared with dynamic systems, the use of which is still very rare. Comparison of ultrasound-assisted leaching with other sorts of leaching, such as Soxhlet, microwave-assisted and supercritical fluid extraction, shows the potential of ultrasound for leaching in a number of areas.

Ultrasound: a powerful tool for leaching

Microplastics cause neurotoxicity, oxidative damage and energy-related changes and interact with the bioaccumulation of mercury in the European seabass, Dicentrarchus labrax (Linnaeus, 1758).

Before the injection--modern methods of sample preparation for separation techniques.

Determination of mercury in environmental and biological samples using pyrolysis atomic absorption spectrometry with gold amalgamation

Critical Review: Analytical Extraction of Additives From Polymers

A simple solvent selection procedure for accelerated solvent extraction (ASE®) of polymers is described using Hildebrand solubility parameters. A series of extractions with a solvent with a solubility parameter several Hildebrand units (MPa1/2 ) different from the polymer are carried out at increasing temperatures until maximum extraction is reached. A second solvent with a solubility parameter close to that of the polymer is then added incrementally at the optimum temperature found from the initial experiments, until a maximum in the extraction rate is reached. This method is used to determine optimum conditions for ASE® of additives from ground polypropylene (PP), poly(vinyl chloride) (PVC) and nylon. Complete extractions were possible of Irganox 1010 (pentaerythrityl tetrakis (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) from freeze ground PP in 18 min (propan-2-ol–cyclohexane (97.5∶2.5) at 140 °C), and dioctyl phthalate (DOP) from PVC in 13 min (hexane–ethyl acetate (60∶40) at 170 °C). ASE® extraction from PVC pellets was possible in reasonable time (1 h) without grinding or cutting the polymer. The results were not significantly different from those obtained by conventional solvent extraction methods. From nylon, 96% extraction of the dimer in 19 min (hexane–ethanol (60∶40) at 170 °C) was possible, compared to the total amount extracted by exhaustive ASE®. The behaviour of poly(ethylene terephthalate) (PET) and poly(methyl methacrylate) (PMMA) was observed with different solvents at high temperature to determine likely optimum extraction conditions. These were ethyl acetate at 190 °C for PET and hexane–ethyl acetate (70∶30) at 150 °C for PMMA.

A simple solvent selection method for accelerated solvent extraction of additives from polymers

This is the latest review covering atomic spectrometric measurements of industrial materials, metals, chemicals and advanced materials. It follows on from last year's review1 and should be read in conjunction with other reviews in the series.2–6 This year has seen the departure of Malcolm Salisbury, one of the writing team for two years. He has, however, been replaced by Sian Shore who is an able successor. Our thanks go to Malcolm for all of his hard work over the period.

 This year's review has a slightly changed format, with the larger sections being split into smaller sub-sections so that the reader may be directed more easily to the parts of the review most relevant to them. In addition, to aid quick reference, the use of Tables has also continued.

 The technique of laser induced breakdown spectrometry (LIBS) is still gathering pace, and its use is expanding into new territory. Similarly, the use of femtosecond laser ablation is also receiving more interest. These laser-based techniques are invaluable tools for the analysis of materials that are very inert, refractory or otherwise difficult to bring into solution or indeed if they are valuable either in terms of monetary value or archaeologically and must therefore have as little damage inflicted on them as possible. The use of chemometric analysis of analytical data is also gaining in popularity, especially for archaeological materials such as pottery/ceramics and glasses. This is largely because the use of chemometrics may facilitate provenance studies, elucidate trade routes etc. In addition, it is also being used increasingly for forensic applications.

 There is a continuing trend for the subject areas to overlap slightly, and hence it is worth noting that some papers may be discussed in more than one section of the review and that other papers may only be discussed once, but possibly not in the most expected place.

 The writing team are keen to elicit feedback from readers of this review and invite you to complete the Atomic Spectroscopy Updates questionnaire on http://www.asureviews.org.

/pdf/atomic-spectrometry-update-industrial-analysis-metals-4w569xe1oh.pdf

Atomic Spectrometry Update—Industrial Analysis: Metals, Chemicals and Advanced Materials

Irganox 1010 (pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)] propionate) is successfully extracted from polypropylene using solvents at high temperatures and pressures in a homemade accelerated solvent extraction system. For example, using freeze-ground polymer, 90% extraction is possible within 5 min with 2-propanol at 150 °C. Extraction curves for 2-propanol and acetone fit well to the “hot ball” model, previously developed for supercritical fluid extraction. Diffusion coefficients are determined for extractions with 2-propanol, acetone, and cyclohexane over a range of temperatures, and the activation energies for the diffusion are 134, 107, and 61 kJ mol-1, respectively. The lower figure for acetone and cyclohexane indicates that these solvents swell the polymer more than does 2-propanol. The polymer dissolves in the solvent at too high a temperature, which causes blockage of the transfer lines. For maximum extraction rates, the highest temperature for each solvent that avoids dissolut...

John Carroll

Papers

Determination of mercury in environmental and biological samples using pyrolysis atomic absorption spectrometry with gold amalgamation

Critical Review: Analytical Extraction of Additives From Polymers

A simple solvent selection method for accelerated solvent extraction of additives from polymers

Atomic Spectrometry Update—Industrial Analysis: Metals, Chemicals and Advanced Materials

Factors affecting high-pressure solvent extraction (accelerated solvent extraction) of additives from polymers.