In Situ Derivatization/Solid-Phase Microextraction: Determination of Polar Aromatic Amines.
In: Analytical Chemistry (Anal.Chem.), Jg. 76 (2004) ; Nr. 4, S. 1028-1038
Zeitschriftenaufsatz / Fach: Chemie
A solid-phase micro-extn. (SPME) gas chromatog.-mass spectrometry (GC/MS) method to det. polar arom. amines in water was developed. Prior to extn., analytes were derivatized directly in water by diazotation and subsequent iodination in a 1-pot reaction. Derivs. were extd. by direct-SPME using a PDMS/DVB fiber and analyzed by GC/MS in the full-scan mode. By diazotation/iodination, analyte polarity was significantly decreased; as a consequence, extn. yields dramatically improved. The derivatization proved suitable for strongly deactivated arom. amines; even very polar diamino compds. were efficiently enriched following derivatization. A total of 18 anilines, comprising a wide range of functional groups which could be detd. simultaneously, were studied. The method was thoroughly validated; precision at a 0.5 mg/L concn. was 3.8-11% relative std. deviation for non-nitrated analytes using aniline-d5 as internal std. and 3.7-10% for nitroarom. amines without internal std. This in-situ derivatization/SPME/GC-MS method was calibrated over the whole anal. procedure and was linear over 2 orders of magnitude. Using 10-mL samples, detection limits of 2-13 ng/L were achieved for 15 of 18 analytes. For 2 aminodinitrotoluene isomers and a diaminonitrotoluene, detection limits were 27-38 ng/L. By allowing quantification at the 0.1 mg/L level, anal. of all target compds. met European Union drinking water regulations. The method provides high sensitivity, robustness, and high sample throughput by automation. It was used with actual water and former ammunition facility wastewater samples to quant. det. several arom. amines.