Dietary exposure assessment of streptomycin and tetracycline in food of animal origin on the Croatian market.

Residual antibacterials in food constitute a risk to human health, particularly because they can contribute to the transmission of antibiotic-resistant pathogenic bacteria through the food chain. This paper presents dietary exposure assessment of streptomycin and tetracycline, based on combining food consumption data in Croatia with data on the concentration of veterinary drugs in analysed samples of food of animal origin. According to the median values, the estimated daily intake of streptomycin and tetracycline through food is 11.9 and 0.7 µg/person/day, respectively. The largest contribution to streptomycin intake comes from meat (4.8 µg/person/day, i.e. 41%), but milk is the largest source for tetracycline (0.3 µg/person/day, i.e. 46%). The estimated dietary exposure to these veterinary drugs does not exceed relevant toxicological reference values and the level of exposure is assessed to be acceptable.

Risk assessment of streptomycin and tetracycline residues in meat and milk on Croatian market.

In addition to biological hazards like bacteria, viruses, parasites, the occurrence of chemical hazards is another characteristic of modern food production. The use of veterinary medicines in intensive production of animals is conditio sine qua non so it is impossible to avoid in full the presence of their residues in food. This paper presents quantitative risk assessment of streptomycin and tetracycline based on acceptable daily intake, daily consumption of milk and meat in Croatia (0.222 and 0.126 kg/person, respectively) and residues of these two veterinary drugs in this type of food. The median value for streptomycin in milk and meat was 11.50 and 38.00 µg/kg, respectively (milk: average: 15.57 µg/kg; range from 0 to 73.82 µg/kg; meat: average 44.14 µg/kg; range from 0 to 278.35 µg/kg). The median value for tetracycline in milk and meat was 1.50 µg/kg (milk: average 1.5 µg/kg; range, from 0 to 4.26 µg/kg; meat: average 1.62 µg/kg; range from 0 to 5.35 µg/kg). Based on the median value it can be concluded that the estimated daily intake of streptomycin and tetracycline through milk and meat in Croatia is low (streptomycin: 7.33 µg/person/day; tetracycline: 0.52 µg/person/day), and the risk is assessed as negligible.

Matrix solid-phase dispersion extraction and gas chromatographic determination of chloramphenicol in muscle tissue.

A method based on matrix solid-phase dispersion (MSPD) was developed for the gas chromatographic (GC) determination of chloramphenicol (CAP) residues in animal muscle tissue. Muscle tissue was blended with octadecylsilyl-derivatized silica (C(18)). A column made from the C(18)/muscle tissue matrix was washed with n-hexane and acetonitrile/water (5 + 95), after which CAP was eluted with acetonitrile/water (50 + 50) and partitioned into ethyl acetate. The final extract was evaporated, and a trimethylsilyl derivative of CAP was prepared with Sylon HTP and detected by GC with an electron capture detector (ECD) and a mass spectrometer. For quantitation, the internal standard used was the meta isomer of CAP (m-CAP) for GC-ECD. Muscle tissue samples were fortified at three concentration levels. At 5, 10, and 15 microg/kg levels the respective mean recoveries were 93, 96, and 98%, and the repeatabilities were 13, 11, and 3%. The detection and quantitation limits with ECD were 1.6 and 4.0 microg/kg, respectively. No statistically significant difference was observed in the efficiency of CAP extraction from muscle tissue of various animals (bovine, porcine, and poultry) by the MSPD technique.