# Determination of Eleven Veterinary Drugs in Chicken Meat and Liver
## 3 Results and Discussion
### Feed Additives
Spectinomycin is an aminocyclitol antibiotic, distinct from the aminoglycos and has a broad-spectrum antibiotic applied in veterinary medicine for mycoplasma infections and for treating organisms with multiple antibiotic resistance [17; 18]. Roxarsone residues in this study determined in 300 chicken meat samples showed concentration values below 70 \(\upmu\)g/kg. This compound is not covered by Brazilian legislation. Roxarsone is an arsenic-basic veterinary drug, which was banned since 2014 and withdrawn from the market [19]. Although arsenic speciation is an important issue to be considered, once the organic form is less harmful than the inorganic one, FDA banned its commercialization [20]. Therefore, if this compound is found in feed or food matrices, it violates legislation, except for China and Middle East, which accept this additive when residues are below the MRL of 500 \(\upmu\)g/kg in chicken meat. Virginiamycin residues in all 300 samples showed values below LQ (20 \(\upmu\)g/kg) in chicken meat. Virginiamycin is used as a feed additive to enhance animal growth in cows, swine, poultry, and fish, and contains lactinic rings that are primarily composed of two anti-bacterial factors, namely M1 and S1 [21]. Only Codex forbids its use [12] and Brazil follows this criterion, although in other legislation it is allowed at MRL = 10-200 \(\upmu\)g/kg, as shown in Table 1.  
Halofuginome hydrobromide residues were found to be LQ < 3 \(\upmu\)g/kg in all 60 analyzed chicken meat samples. It is not authorized by Codex, and Brazil as well as the USA does not use this compound, although it is allowed by other legislations at MRL varying from 10 to 100 \(\upmu\)g/kg in meat. Halofuginone hydrobromide is an antiparasitic agent, which acts against protozoa [8], and is more common to be analyzed in liver. Trenbolone acetate residues in all 60 samples showed values below LQ (2 \(\upmu\)g/kg) in chicken meat. In Brazilian MAPA this compound is only evaluated in swine urine, while other countries have MRL for meat, varying from 2 \(\upmu\)g/kg (Codex, Canada) to 2000 \(\upmu\)g/kg (Middle East) in meat. Trenbolone acetate is a synthetic progestational agent, used mainly as implants under the animal skin of feedlot steers [22]; and usually determined in beef [12] (MRL = 2 \(\upmu\)g/kg) and liver (MRL = 10 \(\upmu\)g/kg); however anabolic steroids are forbidden for food-producing animals in the EU [8], China [9], USA [11] and Brazil [6], although within Brazilian legislation, the MRL = 2 \(\upmu\)g/kg (Table 1) corresponds to the Minimum Required Performance Limit (MRPL) for the analytical method in swine urine. Dinitolmide residues were below LQ = 5 \(\upmu\)g/kg in all 60 evaluated chicken meat samples. It is a nitro amide coccidiostat used in poultry feed and may be harmful to the environment and human health [23] and it is not authorized in Brazil, EU and nor recommended by Codex [6; 8; 12], however it is allowed by Canada, China, USA, and Asian legislation at 3000 \(\upmu\)g/kg (Table 1). Halofuginone hydrobromide, trenbolone acetate and dinitolmide + zoalene are not registered by the national Ministry (MAPA); the country does not have validated methodologies to evaluate such residues as a routine. Therefore, our assays are performed by accredited laboratories, only when demanded by certain importing countries, whose headquarters lays abroad. To maintain the poultry production and exports, it is imperative to continuously educate farmers, by teaching them notions about chemical residue legislation, knowledge about meat inspection, biosecurity measures and animal vaccination, so as to ensure food safety, food security, and public health [24]. Statistical Analyses to Evaluate the Need of Decreasing the National Sampling Plan and Increasing Limit of Non-Compliance  
The sampling procedures are specific to each type of problem to be addressed. With respect to PNCRC applied to products of animal origin, Discrete Probability Models (DPM) are usually adopted.