Simultaneous multichannel mass-specific detection for high-performance liquid chromatography using an array detector sector-field mass spectrometer

Abstract

The use of a separation step, such as liquid chromatography, prior to inductively coupled plasma mass spectrometry (ICP-MS) has become a common tool for highly selective and sensitive analyses. This type of coupling has several benefits including the ability to perform speciation analysis or to remove isobaric interferences. Several limitations of conventional instruments result from the necessity to scan or pulse the mass spectrometer to obtain a complete mass spectrum. When the instrument is operated in such a non-continuous manner, duty cycle is reduced, resulting in poorer absolute limits of detection. Additionally, with scanning instruments, spectral skew can be introduced into the measurement, limiting quantitation accuracy. To address these shortcomings, a high-performance liquid chromatograph has been coupled to an ICP-MS capable of continuous sample introduction and simultaneous multimass detection. These features have been realized with a novel detector array, the focal plane camera. Instrument performance has been tested for both speciation analysis and for the elimination of isobaric interferences. Absolute limits of detection in the sub picogram to tens of picograms regime are obtainable, while the added mass dimension introduced by simultaneous detection dramatically increases chromatographic peak capacity.

Characterization of a Second-Generation Focal-Plane Camera Coupled to an Inductively Coupled Plasma Mattauch−Herzog Geometry Mass Spectrograph

“…The array detector devices, based on Faraday-strip detection, have been termed focal plane cameras (FPC) because of their ability to collect an image of the ion distribution along the focal plane of the double-focusing mass spectrograph. The first-generation detector has been characterized and discussed extensively in previous publications. ,− It was composed of 32 individual ion collectors and will therefore be referred to as FPC-32 in the following discussion. The present paper will focus on the figures of merit of the second-generation detector, which has 128 channels and will be denoted FPC-128.…”