Detector supports: application to aliphatic amines in wastewater

Talanta. 2005 Jan 15;65(1):217-22. doi: 10.1016/j.talanta.2004.06.011.

Abstract

Solid support assisted derivatization coupled to diffuse reflectance spectroscopy (DRS) was proposed and proved useful for the detection and quantification of aliphatic amines in water as an example. Dabsyl chloride (DBS), ninhydrin and sodium 1,2-naphtoquinone 4-sulphonate (NQS) were assayed as derivatization reagents. C(18) and SDB-XC disks and C(18) cartridges were tested for amine retention and after that derivatization. The decrease of the orange colour of dabsyl chloride on SBD-XC disks produced by the formation of its derivative with methylamine in the support (10min at 100 degrees C) allowed the selective determination of the amine at concentration level equal or higher than 0.5mgL(-1). Ninhydrin can be used for methylamine, ethylamine, propylamine, butylamine and pentylamine (between 5 and 15mgL(-1)) by measuring the diffuse reflectance produced by the brown derivative formed in C(18) extraction disks after 15min at 100 degrees C. NQS and C(18) SPE columns can be also employed to estimate amines, but the detection limits were higher than those provided by DBS and Ninhydrin, around 10mgL(-1). As an example, found concentration of methylamine or total amines (expressed as -NH(2)-N mgL(-1)) in a wastewater sample is given employing dabsyl chloride or ninhydrin reagents, respectively with satisfactory results.