An Innovative Approach to Sensitive Artificial Sweeteners Analysis by Ion Chromatography-Triple Quadrupole Mass Spectrometry / 分析化学

ABSTRACT

Artificial sweeteners ( ASs ) have gained more and more attention by environmental scientists because some of them such as acesulfame, have the potential to be the ideal tracers of domestic wastewater for environmental monitoring. In contrast to the existing methods of artificial sweeteners, the analytical method of ASs as a new tracer for environmental samples requires better sensitivity and selectivity to avoid matrix interference. A highly sensitive method for the simultaneous determination of four frequently-used artificial sweeteners in water samples using solid-phase extraction and ion chromatography triple quadrupole mass spectrometer with an electrospray ionization source ( IC-MS/MS) in negative ion mode was developed. The separation effect of different separation columns was compared and a 2-mm ion chromatography column AS19 was chosen in the experiment. Chromatographic separation of all the 4 artificial sweeteners was carried out in 9 min in isocratic elution mode using 60 mmol/L sodium hydroxide as eluent. Different kinds of solid phase extraction cartridges were evaluated to obtain satisfactory recoveries of all of the analytes. Merk LiChrolut EN (200 mg, 3 mL) was preconditioned with 2 mL of methanol, followed by 2 mL of H2 O. About 200 mL of sample (pH<2. 0) was passed through the cartridge at a flow rate of 4 mL/min, and then the cartridge was eluted using 2 mL of methanol. 2 mm suppresser (75 mA) was used to reduce the background noise and to remove the matrix interference. The limits of detection were below 5. 0 ng/L for various artificial sweeteners based on 3-fold the S/N. The recoveries of different matrices in the samples were 65%-120%. The method described here is time-saving, accurate and precise, and is suitable for monitoring artificial sweeteners in different water matrices. The method has also the potential to trace other contaminants in groundwater.