Objective To develop a method of pulsed direct current electrospray ionization mass spectrometry(pulsed-dc-ESI-MS)for rapid detection of 4 kinds of amphetamines in saliva.Methods Saliva samples were adjusted to optimal pH using NaOH,followed by protein precipitation with anhydrous magnesium sulfate and liquid-liquid extraction with ethyl acetate.The supernatant was then analyzed via pulsed-dc-ESI-MS.Results The limits of detection were 0.01～0.5 ng/mL and the limits of quantitative were 1.0～5.0 ng/mL.In addition,in the concentration range,4 amphetamines have good linear relationships,the correlation coefficients(R2)were all greater than 0.999,the recoveries of 97.21%～104.70%and the relative standard deviations(RSDs)were less than 10%.Conclusion The method has the advantages of simple operation,fast detection,high sensitivity,selectivity and good stability.It can be used for on-site rapid detection of amphetamines in saliva.

Objective To develop a method of pulsed direct current electrospray ionization mass spectrometry(pulsed-dc-ESI-MS)for rapid detection of 4 kinds of amphetamines in saliva.Methods Saliva samples were adjusted to optimal pH using NaOH,followed by protein precipitation with anhydrous magnesium sulfate and liquid-liquid extraction with ethyl acetate.The supernatant was then analyzed via pulsed-dc-ESI-MS.Results The limits of detection were 0.01～0.5 ng/mL and the limits of quantitative were 1.0～5.0 ng/mL.In addition,in the concentration range,4 amphetamines have good linear relationships,the correlation coefficients(R2)were all greater than 0.999,the recoveries of 97.21%～104.70%and the relative standard deviations(RSDs)were less than 10%.Conclusion The method has the advantages of simple operation,fast detection,high sensitivity,selectivity and good stability.It can be used for on-site rapid detection of amphetamines in saliva.