Evaluation of Different Parameters in the Extraction of Incurred Pesticides and Environmental Contaminants in Fish

Abstract

Sample processing is often ignored during analytical method development and validation, but accurate results for real samples depend on all aspects of the analytical process. Also, validation is often conducted using only spiked samples, but extraction yields may be lower in incurred samples. In this study, different variables in extraction for incurred pesticides and environmental contaminants in fish were investigated. Among 207 analytes screened using low-pressure gas chromatography-tandem mass spectrometry, consisting of 150 pesticides, 15 polycyclic aromatic hydrocarbons (PAHs), 14 polychlorinated biphenyls (PCBs), 6 polybrominated diphenyl ethers (PBDEs), and 22 other flame retardants (FRs), 35 (16 pesticides, 9 PCBs, 5 PBDEs, and 5 PAHs) were identified for quantification in samples of salmon, croaker, and NIST Standard Reference Material 1947 (Lake Michigan Fish Tissue). Extraction efficiencies using different extraction devices (blending, vortexing, and vibrating) versus time, sample size, and sample/solvent ratio were determined. In comparison to blending results, use of a pulsed-vortexer for 1 min with 1/1 (g/mL) sample/acetonitrile ratio was generally sufficient to extract the incurred contaminants in the homogenized fish tissues. Conversely, extraction with a prototype vibration shaker often took 60 min to achieve 100% extraction efficiency. A main conclusion from this study is that accurate results for real samples can be obtained using batch extraction with a pulsed-vortexer in a simple and efficient method that achieves high sample throughput.

Efficient Matrix Cleanup of Soft-Gel-Type Dietary Supplements for Rapid Screening of 92 Illegal Adulterants Using EMR-Lipid dSPE and UHPLC-Q/TOF-MS

“…Therefore, In DLLME methods, it is necessary to select suitable dispersion and extractant solvents. In previous studies, the influence of several dispersive solvents, such as methanol, acetone, and acetonitrile, was investigated [29][30][31]. Although methanol and acetonitrile as dispersive solvents were shown to have similar extraction efficiencies, taking into consideration matrix co-extraction led to acetonitrile being selected as dispersive solvent for soft-gel samples.…”

Method validation for 243 pesticides and environmental contaminants in meats and poultry by tandem mass spectrometry coupled to low-pressure gas chromatography and ultrahigh-performance liquid chromatography

“…All samples were filleted into skinless and boneless pieces, frozen and comminuted with dry ice using a Robot Coupe (Ridgeland, MS; USA) RSI 2Y1 chopper to produce a fine powder, which were stored in glass jars at -18°C until analysis. A Glas-Col (Terre Haute, IN; USA) platform pulsed-vortexing mixer was used for extraction, (Sapozhnikova & Lehotay, 2015) and a ThermoFisher (Waltham, MA; USA) Sorvall Legend RT centrifuge was used for centrifugation.…”

“…For example, a sample test portion of 5 g rather than 10 g was used to save cost of reagents while still representing the bulk sample, in accordance with finding from a recent study. (Sapozhnikova & Lehotay, 2015) Several experiments were conducted to re-assess and optimize the method for the new matrices. For example, the use of APs was evaluated and integrated into the final LPGC-MS/MS method.…”

Use of an Efficient Measurement Uncertainty Approach To Compare Room Temperature and Cryogenic Sample Processing in the Analysis of Chemical Contaminants in Foods

“…showed that the same degree of analyte variability could be achieved for a 5 g test sample when using dry ice as 110 g at room temperature, whereas for orange, a subsample size of 5 g provided sufficient homogeneity for both sample processing procedures . Another study showed that, in the case of fish filets, 2 g subsamples were sufficiently representative when using cryogenic conditions …”

“…This bulk sample is then comminuted to generate a representative test sample portion, typically 10–50 g, for analysis. , As a result of resource limitations and sample throughput needs, sample processing in most routine laboratories is conducted at room temperature. However, it has been demonstrated that cryogenic processing using dry ice (solid CO 2 ) or liquid nitrogen often produces more reliable results. − For chlorpyrifos in tomato using a specific chopper, Fussell et al. showed that the same degree of analyte variability could be achieved for a 5 g test sample when using dry ice as 110 g at room temperature, whereas for orange, a subsample size of 5 g provided sufficient homogeneity for both sample processing procedures .…”