Recoveries of mercury from spiked fish samples were 92–102%. The inter-laboratory calibration study, with the Ministry of Agriculture, Food and Fisheries laboratory at Burnham on Crouch, Essex, centred on 21 samples from three marine and one freshwater fish species. The 21 samples contained varying amounts of fat or oil and muscle mercury concentrations in the range 0.13–1.27 mg kg-1 fresh weight. The results showed recoveries in the range of 95–104% of those obtained by MAFF, the mean recovery being 96.2%. These recoveries are consistent with the standards of interlaboratory calibration for mercury analysis – Munns and Holland, and are acceptable when compared with other studies – Utheet al. The lowest recoveries were associated with fish
containing more oil/fat than average.