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Quaternary ammonium compounds (QACs) are broad-spectrum disinfectants used in a range of everyday materials. Their high usage rates, limited regulation and reporting has meant their environmental release is largely uncontrolled and impact unknown. With links to antimicrobial resistance (AMR) and adsorption to wastewater solids (that are recycled), there is a need for more controlled disposal measures and monitoring. These environmental matrices are highly complex requiring methods that are often laborious and costly to undertake. Using a robust quantitative reversed-phase LC-MS/MS method, we have shown that an ‘off the shelf’ QuEChERS product can reliably extract (

The use of three C18 sorbents in matrix solid phase dispersion (MSPD) for the determination of clenbuterol in bovine liver fortified at 5 ng g-1 is described. MSPD grade C18 sorbents give rise to more efficient blending and packing of the material for subsequent washing and analyte elution in comparison with a non-MSPD grade C18 sorbent. Following enzymatic deconjugation of the liver extracts, radioimmunoassay is used as the method of determination. The mean recovery of clenbuterol with all sorbents is comparable and within the range 86-96% in two intra-assay studies (n = 3). The liver extracts in each case are highly coloured. The variation in recovery is observed to be lowest with MSPD grade C18 (end-capped). This sorbent was used in further studies to evaluate the use of solid phase extraction (SPE), post MSPD, with normal phase aminopropyl or mixed mode cation exchange columns for extract purification. The mean recovery of clenbuterol (n = 4, inter-assay study) following MSPD and normal phase SPE clean-up was 95 +/- 15% and 89 +/- 9% at fortification levels of 1 and 2.5 ng g-1, respectively.