Combination of headspace solid phase extraction with lighter than water organic solvent-based dispersive liquid-liquid microextraction for the extraction of residual solvents from herbal laxative medicine prior to gas chromatography-flame ionization detection

Combination of headspace solid phase extraction with lighter than water organic solvent-based dispersive liquid-liquid microextraction for the extraction of residual solvents from herbal laxative medicine prior to gas chromatography-flame ionization detection