Freeze drying reduces the extractability of organochlorine pesticides in fish muscle tissue by microwave-assisted method

Abstract This paper describes a comparative study of 2 extraction methods, pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE), for the determination of organochlorine pesticides (OCPs) in fish muscle samples. In both cases, samples were extracted with hexaneacetone (50 + 50), and the extracts were purified by solid-phase extraction using a carbon cartridge as the adsorbent. Pesticides were eluted with hexaneethyl acetate (80 + 20) and determined by gas chromatography with electron-capture detection. Both methods demonstrated good linearity over the range studied (0.0050.100 g/mL). Detection limits ranged from 0.029 to 0.295 mg/kg for PLE and from 0.003 to 0.054 mg/kg for MAE. For most of the pesticides, analytical recoveries with both methods were between 80 and 120, and the relative standard deviations were <10. The proposed methods were shown to be powerful techniques for the extraction of OCPs from fish muscle samples. Although good recovery rates were obtained with both extraction methods, MAE provided advantages with regard to sample handling, cost, analysis time, and solvent consumption. Acceptable validation parameters were obtained although MAE was shown to be more sensitive than PLE.

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Rapid Method for the Determination of Organochlorine Pesticides and PCBs in Fish Muscle Samples by Microwave-Assisted Extraction and Analysis of Extracts by GC-ECD

Journal of AOAC International ◽

10.1093/jaoac/93.6.1987 ◽

2010 ◽

Vol 93 (6) ◽

pp. 1987-1994 ◽

Cited By ~ 8

Author(s):

Angelika M Wilkowska ◽

Marek Biziuk

Keyword(s):

Organochlorine Pesticides ◽

Fish Muscle ◽

Food Samples ◽

Fat Content ◽

Clupea Harengus ◽

Microwave Assisted Extraction ◽

Extraction Solvent ◽

Microwave Assisted ◽

Assisted Extraction

Abstract A procedure for the multiresidue determination of organochlorine pesticides and polychlorinated biphenyls in fish muscle samples has been developed. The method is based on the microwave-assisted extraction (MAE) of food samples from an acetonitrilewater (95 5, v/v) mixture followed by SPE cleanup of the extracts and analysis by GC with an electron capture detector. MAE operational parameters, such as the extraction solvent, temperature, and time, were optimized with respect to the extraction efficiency of the target compounds from food samples with 1013 fat content. The chosen extraction technique allows reduction of the solvent consumption and extraction time when compared with methods already used. Acetonitrile is a good extraction solvent for low-fat matrixes (220 fat content), such as fish samples, because it does not significantly dissolve the highly polar proteins, salts, and sugars commonly found in food and gives high recoveries of a wide polarity range of analytes. For purification, SPE using LC-Florisil was shown to be sufficient for the removal of coextracted substances. Recoveries >78 with RSD values <15 were obtained for all compounds under the selected conditions. Method quantification limits were in the 510 g/kg range. The method was applied to the analysis of samples of herring (Clupea harengus) purchased at the local fish market. The method is rapid and reliable for the determination of organochlorine analytes in fish muscle.

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Preparation and application of carbon and hollow TiO2 microspheres by microwave heating at a low temperature

e-Polymers ◽

10.1515/epoly-2021-0014 ◽

2021 ◽

Vol 21 (1) ◽

pp. 200-209

Author(s):

Caiyun Zhang ◽

Chunhong Li ◽

Bolin Ji ◽

Zhaohui Jiang

Keyword(s):

Low Temperature ◽

Microwave Heating ◽

Raw Material ◽

Carbon Microspheres ◽

Microwave Assisted ◽

The Core ◽

Good Crystallinity ◽

Carbon Core ◽

Microwave Assisted Method ◽

Uniform Particle Size

Abstract A fast, simple, and energy-saving microwave-assisted approach was successfully developed to prepare carbon microspheres. The carbon microspheres with a uniform particle size and good dispersity were prepared using glucose as the raw material and HCl as the dehydrating agent at low temperature (90°C) in an open system with the assistance of microwave heating. The carbon microspheres were characterized by elemental analysis, XRD, SEM, FTIR, TG, and Raman. The results showed that the carbon microspheres prepared under the condition of 18.5% (v/v) HCl and heating for 30 min by microwave had a narrow size distribution. The core–shell structure of the carbon core and TiO2 shell was prepared with (NH4)2TiF6, H3BO3 using the microwave-assisted method. The hollow TiO2 microspheres with good crystallinity and high photocatalytic properties were successfully prepared by sacrificing the carbon microspheres.

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