Chemical decontamination of methamphetamine and ephedrine using household hypochlorite bleach

Hypochlorite bleach is an easily accessible, commonly used cleaning product. Methamphetamine and ephedrine hydrochloride react rapidly with 3.5 g/L (1:8 dilution of a commercial household bleach) and 21 g/L (2:1 dilution) solutions of sodium hypochlorite bleach in water, with each reaction being complete within 5 min of mixing. The major methamphetamine reaction product was identified as N-chloromethamphetamine which was reliably quantified by dechlorination using a sulfite quench prior to sample extraction and analysis by gas chromatography – mass spectrometry (GC–MS). The initial product from ephedrine was benzaldehyde, and this then formed benzoic acid as a second-generation product in the 3.5 g/L sodium hypochlorite bleach solution.

N-Chloromethamphetamine was observed to persist in solution for several hours with minor formation of benzaldehyde and N-chloro-1-phenylpropan-2-imine, a proposed second-generation product from N-chloromethamphetamine, also detected. Assessment of further N-chloramine reaction products will aid in our ability to estimate exposure risks to those attempting drug remediation using hypochlorite bleach. These observed products can also be used as potential forensic markers of the use of a property for illicit activity if bleach has been used in an attempt to decontaminate the location.