Trace elements and heavy metals in poultry and livestock meat in Taiwan.

Trace elements and heavy metals were determined in poultry and livestock meat by inductively coupled plasma mass spectrometry after graphite block digestion. Samples were collected from markets in Taiwan and included beef (20), mutton (20), pork (30), chicken (30), duck (10) and goose (10). Mean concentrations of Mn, Co, As, Se, Mo, Cd, Sb and Pb in meat samples were 0.106-0.365 µg/g, 0.002-0.033 µg/g, 0.005-0.035 µg/g, 0.108-0.349 µg/g, 0.029-0.140 µg/g, <0.002-0.003 µg/g, <0.002-0.004 µg/g and 0.009-0.046 µg/g, respectively. Arsenic concentrations in both pork and chicken were higher than in other meat. Lead concentrations were higher in duck. Risk assessment from these data did not indicate harm for public health.

Determination of methylmercury in fish using focused microwave digestion following by Cu2+ addition, sodium tetrapropylborate derivatization, n-heptane extraction, and gas chromatography-mass spectrometry.

The analytical procedure for analysis of methylmercury in fish was developed. It involves microwave-assisted digestion with alkaline solution (tetramethylammonium hydroxide), addition of Cu2+, aqueous-phase derivatization of methylmercury with sodium tetrapropylborate, and subsequent extraction with n-heptane. The methylmercury derivative was desorbed in the splitless injection port of a gas chromatograph and subsequently analyzed by electron impact mass spectrometry. Optimum conditions allowed sample throughout to be controlled by the instrumental analysis time (near 7 min per sample) but not by the sample preparation step. At the power of 15-30, 45, and 60-75 W, sample preparation time is only 3.5, 2.5, and 1.5 min, respectively. The proposed method was finally validated by the analysis of three biological certified reference materials, BCR CRM 464 tuna fish, NRC DORM-2 dogfish muscle, and NRC DOLT-2 dogfish liver. The detection limit of the overall procedure was found to be 40 ng/g of biological tissue for methylmercury. The recovery of methylmercury was 91.2-95.3% for tuna, 89.3-94.7% for marlin, and 91.7-94.8% for shark, respectively. The detected and certified values of methylmercury of three biological certified reference materials were as follows: 5.34 +/- 0.30 microg/g (mean +/- S.D.) and 5.50 +/- 0.17 microg/g for CRM 464 tuna fish, 4.34 +/- 0.24 and 4.47 +/- 0.32 microg/g for NRC DORM-2 dogfish muscle, and 0.652 +/- 0.053 and 0.693 +/- 0.055 microg/g for NRC DOLT-2 dogfish liver, respectively. It indicated that the method was well available to quantify the methylmercury in fish.