Development of solid-phase extraction method for the determination of aromatic sensitisers in paper mill effluent

In this paper, a procedure for the determination of 11 aromatic hydrocarbon-type sensitisers and their related compounds from water samples, used in the manufacture of thermal paper, is presented. The compounds were extracted using a solid-phase extraction (SPE) cartridge with an octadecyl (C18) or a phenyl-bonded silica (PH) sorbent and then determined by gas chromatography-mass spectrometry (GC-MS). Factors affecting the performance of the extraction steps were thoroughly evaluated, and their effects on the yield of the sample preparation were discussed. Under optimised experimental conditions, SPE cartridges were conditioned with 10mL hexane followed subsequently by 10mL methanol, loaded with water sample at 2mL min(-1), and eluted with 10mL hexane at 1.5mL min(-1). The limits of detection and quantification, calculated for signal-to-noise ratios of 3 and 10, were in the range of 1-5 mu g L-1 and 2.5-10 mu g L-1, respectively. Recovery yields of the present method using river water were in the range of 88%-112% with a C18 sorbent and 86%-116% with a PH sorbent. The repeatability, expressed as a relative standard deviation, was in the range of 2.8%-11% with a C18 sorbent and 0.7%-9.7% with a PH sorbent (n = 4). Analysis of paper mill effluents revealed the presence of aromatic hydrocarbon-type sensitisers with maximum concentrations of up to 5.2 mu g L-1.