Measurement of serum salicylate levels by solid‐phase extraction and desorption/ionization on silicon mass spectrometry

Abstract

The applicability of the matrix-free laser desorption/ionization on silicon mass spectrometry (DIOS-MS) to measuring serum drug levels was examined by analyzing serum salicylic acid. The optimized and simple solid-phase extraction (SPE) allowed good recovery, 88.9 +/- 5.8%, for 1.4 mM (200 mg/L) of salicylic acid in serum. The negative ion MS allowed measurements of deprotonated molecules without interference from other signals. Using a deuterium-labeled internal standard, good linearity was obtained in the 0.14 to 4.2 mM (20-600 mg/L) range, which was sufficient for monitoring the therapeutic anti-inflammatory dose. SPE followed by DIOS-MS is anticipated to be a method of measuring drug levels in blood and may allow high throughput analysis.

Evaluation of a new matrix‐free laser desorption/ionization method through statistic studies: comparison of the DIAMS (desorption/ionization on self‐assembled monolayer surface) method with the MALDI and TGFA‐LDI techniques

“…With regard to the applicability of the matrix‐free LDI methods in the analyses of low molecular compounds whose ions could interfere with the matrix ions in MALDI, the present study is applied to the detection of salicylic acid in DIAMS. Note that this compound was previously analyzed in DIOS MS using the negative ion mode 26. For the DIAMS/MS study, we have chosen the positive ion mode for the glyceride analysis.…”

A novel laser desorption/ionization method using through hole porous alumina membranes

“…To date a number of ionization techniques that belong to SALDI have been proposed,1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, ...…”

“…The techniques in the other category utilize planar solid substrates with fine structures on the uppermost surface layer as the target plate, so that the photon energies of the laser can reach analytes which are spread over and adsorbed onto the surface and achieve desorption and ionization of analytes 20, 23, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80. Desorption Ionization on Silicon (DIOS) is the representative technique in this category 46.…”

Quantitative Analysis of an Antioxidant Additive in Insoluble Plastics by Surface-Assisted Laser Desorption/Ionization Mass Spectrometry (SALDI-MS) Using TiO2 Nanoparticles

“…16), 17) Briefly, n-type silicon (100) wafers with resistivity r῍0.008῍0.02 Wcm were obtained from Sumitomo Mitsubishi Silicon Corporation (Tokyo, Japan). They were anodically etched in a 1 : 1 (v/v) solution of ethanol (EtOH)-HF (46ῐ) under exposure to white light using a 100 W tungsten filament bulb at a distance of 20 cm.…”

“…As a result, DIOS-MS has been widely used for the analysis of a variety of compounds, including peptides, 12) low molecular weight organic molecules 14) and synthetic, hydrophilic polymers 15) such as surfactants and polyethylene glycol. DIOS-MS without the use of matrix can be regarded as a more quantitative method than MALDI-MS. DIOS-MS has also been used in the qualitative analysis of polymer additives 16) and the quantitative analysis 17) of salicylic acid in serum. More recently, surface-assisted laser desorption/ ionization mass spectrometry (SALDI-MS), in which nanomaterials are used, has received considerable attention because the method does not require the use of organic compounds as a matrix.…”