The quantities are very small, but in milk powder and in meat-based baby food, residues（剩余物） of drugs given to livestock were found. Researchers from the University of Almeria (Spain) have developed a system to analyse these substances quickly and precisely. Antibiotics, such as tilmicosine, or antiparasitic（抗寄生虫的） drugs, such as levamisole, are given to livestock in order to avoid illness, but they can remain later in food. Scientists from the University of Almeria (UAL) have confirmed this, whilst checking new methodology to identify the minute quantities of these substances that remain in baby food preparations.

"The concentrations detected have been generally very low. On one hand, this suggests they are not worrying amounts, on the other hand, it shows the need to control these products to guarantee food safety" Antonia Garrido, Professor of Analytical Chemistry at UAL, pointed out.

With this objective, the team has developed a 'multi-residue' method, which allows several drugs to be detected at a time in baby food. Chromatographic techniques are used for this, in order to separate compounds, and mass spectrometry（质朴分析法） to identify them.

The "precise, simple and fast" methodology has been validated by analysing twelve meat products (cow, pig or poultry) and nine milk powder samples. Data indicate that concentrations of veterinary drugs vary from 0.5 to 25.2 µg/kg in the former and 1.2 to 26.2 µg/kg in the latter "although with more samples, more conclusive results would be obtained."