Operator care and eco-concerned development of a fast, facile and economical assay for basic nitrogenous drugs based on simplified ion-pair mini-scale extraction using safer solvent combined with drop-based spectrophotometry

► The mini-scale ion pair extraction in typical microcentrifuge tubes provided a fast, facile and economical assay for basic nitogenous drugs. ► All reagents and procedures were delicately chosen and the method achieved good analytical performance and had reagent-saving, safe-for-analyst and eco-friendly features. ► It could overcome the drawbacks of the pharmacopeial large-scale extraction and some limitations of novel microextraction techniques. ► It is a paradigm for the development of green pharmaceutical and chemical analysis.