Chemical vapor generation coupled with atomic fluorescence spectrometry for the determination of manganese in food samples

A novel method based on chemical vapor generation (CVG) coupled with atomic fluorescence spectrometry (AFS) for the determination of manganese was developed. Room temperature ionic liquids (RTILs) combined with ammonium pyrroldinedithiocarbamate (APDC) were used to synergetically enhance the CVG of Mn. Volatile species of Mn were effectively generated through reduction of acidified analyte solutions in the presence of 0.1% (m/v) APDC and 0.1% (v/v) 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM]PF6) with 2.0% (m/v) KBH4 and 0.1% (m/v) phenanthroline mixed solution. The efficiency for the CVG of manganese was 44%. Some parameters that influenced CVG and subsequent determination were evaluated in detail, such as the concentrations of RTILs, APDC, phenanthroline, nitric acid (HNO3) and KBH4; lengths of reaction tube and transfer tube, as well as interferences. Under optimized experimental conditions, the detection limit (LOD) of Mn(II) was 1.5 ng mL− 1. Relative standard deviations for five replicate determinations of the standard solution containing 100 ng mL− 1 Mn(II) was 4.3%. The proposed method was successfully applied to the determination of Mn in water sample and certified environmental reference materials with satisfactory results.