a drug detection apparatus for identifying whether a gas sample contains an acidic gas includes a reactor having a gas inlet , a detection reagent containing an oxidant and a reductant , and a catalyst triggering a chemical adsorption with the oxidant and the reductant . a drug detection method applied to a drug detection apparatus is also disclosed . the drug detection apparatus and method can detect the acidic gases from drugs immediately , sensitively and selectively , thereby improving the efficiency of suspect inspection of drug smuggling in airports .