@article{bergo_correa_nagem_augusti_nascentes_2009,  title={Simultaneous quantification of amphetamines and ephedrines in urine by GC/MS using analytical-grade acetic anhydride/pyridine as derivatizing reagents: a suitable approach to reduce costs of routine analyses},  volume={20},  ISSN={0103-5053},  url={https://doi.org/10.1590/S0103-50532009000200021},  DOI={10.1590/S0103-50532009000200021},  number={2},  journal={Journal of the Brazilian Chemical Society},  publisher={Sociedade Brasileira de Química},  author={Bergo, Patrícia L. de Souza and Correa, Joane M. and Nagem, Tanus J. and Augusti, Rodinei and Nascentes, Clésia C.},  year={2009},  pages={348–359} }