FI-ICP-TOFMS for quantification of biologically essential trace elements in cerebrospinal fluid – high-throughput at low sample volume

Abstract

A high-throughput ICP-TOFMS method is presented for multi-element quantification in CSF material requiring low sample volume.

Multicollector Inductively Coupled Plasma–Mass Spectrometry with 1013 Ω Faraday Cup Amplifiers for Ultrasensitive Mg Isotopic Analysis of Cerebrospinal Fluid Microsamples

“…5 and 400 μL aliquots of the quality control CSF material were analyzed for method validation. The concentration of Mg in the quality control CSF determined by SF-ICP-MS was 39.4 ± 1.1 μg mL –1 (2SE, N = 6), which is in agreement with earlier reported data . The Mg recovery obtained after the chromatographic separation was 98.3 ± 2.8% (2SE, N = 6 separate digests), ensuring that on-column isotopic fractionation would not affect the final Mg isotope ratio results.…”

Flow techniques in the analysis of biological samples by inductively coupled plasma mass spectrometry – a review

“…Summing up, CSF samples have a complex matrix, their number and volume are limited, and elements occur in them in low concentrations. Such features make them a perfect example and opportunity for the FA capability demonstration, but sadly only a few papers 38,120,121 are dedicated to it and its connection with ICP-MS.…”

Microsampling of biological fluids for elemental and isotopic analysis by ICP-MS: strategies and applications for disease diagnosis

“…Still, efforts aimed at the analysis of micro-volumes of CSF were pursued. For instance, Theiner et al 45 developed a high-throughput quantitative multi-elemental method for CSF specimens by flow injection of undiluted CSF, requiring sample volumes of only 5 μL. Also, direct injection of small volumes of CSF employing total consumption systems operating at high temperature prior to the CRC-ICP-MS determination has been carried out.…”

“…However, for complex samples the risk of nebulizer obstruction exists. An alternative option to the continuous aspiration is the introduction of tiny volumes (a few microliters 38,45 or even nanoliters 36 ) of samples in a discrete mode (flow injection in a liquid carrier, or segmented-flow injection in a continuously aspirated gas such as air), giving rise to transient signals. Due to the fast data acquisition capability of modern scanning ICP-MS devices (dwell time of a few ms), the transient signal when using a micronebulizer can reach a plateau for a few microliters ( e.g.…”

“…2.5–10 μL) of solution injected (samples or standards), allowing for the analysis of several isotopes in each plug; of course, higher multielemental capabilities will be achieved with an ICP-TOFMS system. 45 On the other hand, in the segmented-flow injection mode, as the carrier stream is not a liquid, the extent of sample re-nebulization from the chamber walls and the sample dispersion in liquid phase is reduced. 37,38 Nonetheless, reported RSD values for 10 μL injections of 1 : 25 diluted blood samples were higher than those obtained by the continuous aspiration mode, these results being attributed to possible small changes in the sample volume injected into the air carrier stream.…”