Fig. 5
From: Penicillin-G and oxytetracycline residues in beef sold for human consumption in Maroua, Cameroon
![Fig. 5](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40550-017-0062-x/MediaObjects/40550_2017_62_Fig5_HTML.gif)
Chromatograms of standards of oxytetracycline (a), penicillin G (b) and two samples containing oxytetracycline (c) and penicillin G (d) residues