Stability study of veterinary drugs in standard solutions for LC-MS/MS screening in food.

A study on stability of veterinary drugs in standard solutions stored at -80°C and at -20°C was conducted over 1 year. Data were acquired on 152 individual stock standard solutions and also on 15 family mixes and 2 working standard solutions. All solutions were prepared, stored and compared 1 year later against freshly prepared ones by LC-MS/MS.