SINGLE SHORT-COLUMN LIQUID-CHROMATOGRAPHY WITH ATMOSPHERIC-PRESSURE CHEMICAL-IONIZATION (TANDEM) MASS-SPECTROMETRIC DETECTION FOR TRACE ENVIRONMENTAL-ANALYSIS

Single short, i.e. ca 2-cm long, high-pressure-packed columns coupled with mass spectrometric (MS) or tandem MS detection enable rapid trace -level determination and identification of environmental pollutants in water samples. In this study an atmospheric pressure chemical ionizat ion (APCI) interface has been used and the overall set-up was tested w ith a mixture of seventeen pesticides, including organophosphates, car bamates, phenylureas and triazines. For the majority of the test analy tes, the most prominent peaks in the positive-ion APCI-MS spectra resu lted from protonated molecules. For fifteen out of the seventeen pesti cides short-column liquid chromatography (LC)-APCI-MS of water samples as small as 15 mL resulted in detection limits between 0.03 and 5 mu g L(-1) in full-scan mode and between 2 and 750 ng L(-1) by selected i on monitoring (SIM), both recorded in the positive-ion mode. Productio n spectra from protonated molecules of the majority of the selected pe sticides present at a level of 0.1 mu g L(-1) in tap water are success fully identified from a search against a pesticide MS-MS library compi led in-house. This short-column LC-APCI-MS(-MS) approach has, on the b asis of full-scan positive-ion data and their product-ion spectra, als o been used to confirm the identity of target compounds and to identif y unknown organic micropollutants in environmental waters.