Multiresidue Determination of Endosulfan and Metabolic Derivatives in Human Adipose Tissue Using Automated Liquid Chromatographic Cleanup and Gas Chromatographic Analysis

Abstract

A multiresidue method based on normal-phase liquid chromatography (LC) cleanup and gas chromatography-electron capture detection-mass selective detection (GC-ECD-MSD) analysis has been developed for the determination of endosulfan and its main metabolic derivatives in human adipose tissues. Analytes were extracted by dissolving the fat samples in n-hexane, and the hexanic extracts were directly injected onto the silicagel column of the automated LC cleanup system. Purified LC extracts were analyzed by GC-ECD or GC-MSD, without any solvent exchanges or preconcentration steps. The high efficiency of the high-performance liquid chromatographic cleanup for the elimination of fats allowed to reach detection limits for all analytes at low nanograms-per-gram concentration levels. The optimized overall analytical procedure was applied to 18 selected human mammary adipose and abdominal fat tissue samples. p,p'-DDE, hexachlorobenzene, and beta-HCH were the most frequently detected compounds, and residues of endosulfan-sulfate and -ether were also found in several samples. All findings were confirmed by an additional GC-MS-MS analysis of the LC sample extracts.

Determination of organochlorine compounds in human adipose tissue using automated liquid chromatographic clean up and gas chromatography—tandem mass spectrometry

“…Samples were prepared and extracted as previously described [26]. After thawing at room temperature, approximately 0.25 0.5 g of wet tissue were chopped and homogenised with enough anhydrous sodium sulphate to eliminate the water, and extracted twice with 5 mL of n-hexane shaking in a vortex for 3 min.…”

“…Normal phase liquid chromatography (NPLC) has been successfully used in our laboratory for the analysis of OCs in whale tissues, including blubber [4], organophosphorus pesticides in marine organisms [25] and also for the determination of endosulfan and its metabolites in human adipose tissue [26]. This technique has several advantages, including short clean up time, a high degree of automation and high efficiency in the elimination of the fat.…”

“…Electron capture detection has been traditionally used for this purpose, but nowadays it is preferable to use mass spectrometry detection in order to verify peak identity. The use of MS detection clearly increases detection capabilities giving spectral identification of separated compounds, but in some cases the use of typical ELMS detection suffers from peak detection problems even when using selected ion monitoring for quantitation, especially when dealing with complex matrices such as biological samples [26]. This situation can be overcome by using tandem mass spectrometry with an adequate selection of precursor and product ions as referenced in the literature [29 30].…”

Pathology of Endosulfan

“…1992). Residues of endosulfan have been detected in multiple human tissues including blood, fetal placenta, breast milk, and mammary adipose tissue (Hernandez et al, 2002;Cerrillo et al, 2005). Acute accidental or intentional ingestion of large amounts of endosulfan resulted in death in humans.…”

GC‐MS/MS multi‐residue method for the determination of organochlorine pesticides, polychlorinated biphenyls and polybrominated diphenyl ethers in human breast tissues

“…In the case of fatty samples, the determination of OCs and PBDEs usually requires a purification sample pretreatment to eliminate lipids present in samples. This clean-up step can be carried out by gel permeation chromatography [22,26], adsorption chromatography with florisil or acidified silica gel columns [27 -28], normal-phase HPLC [9,29], SPE [10], or by chemical treatment with H 2 SO 4 [12,30].…”