title: Air-segmented continuous-flow visible spectrophotometric determination of cephalosporins in drug formulations by alkaline degradation to hydrogen sulphide and formation of methylene blue and determination of sulphide-producing impurities including cephalosporins in penicillin samples.
mesh_terms: D002511:Cephalosporins / Q000302:isolation & purification*; D004340:Drug Contamination / Q000032:analysis; D006862:Hydrogen Sulfide; D008751:Methylene Blue; D010406:Penicillins / Q000032:analysis*; D013053:Spectrophotometry / Q000379:methods
chemical_list: D002511:Cephalosporins; D010406:Penicillins; D008751:Methylene Blue; D006862:Hydrogen Sulfide