Premium
Sieve‐based device for MALDI sample preparation. III. Its power for quantitative measurements
Author(s) -
Molin Laura,
Cristoni Simone,
Seraglia Roberta,
Traldi Pietro
Publication year - 2011
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1885
Subject(s) - chemistry , analyte , molar concentration , matrix (chemical analysis) , sieve (category theory) , sample preparation , quantitative analysis (chemistry) , analytical chemistry (journal) , chromatography , deposition (geology) , homogeneous , paleontology , physics , mathematics , organic chemistry , combinatorics , sediment , biology , thermodynamics
Abstract The solid sample inhomogeneity is a weak point of traditional MALDI deposition techniques that reflects negatively on quantitative analysis. The recently developed sieve‐based device (SBD) sample deposition method, based on the electrospraying of matrix/analyte solutions through a grounded sieve, allows the homogeneous deposition of microcrystals with dimensions smaller than that of the laser spot. In each microcrystal the matrix/analyte molar ratio can be considered constant. Then, by irradiating different portions of the microcrystal distribution an identical response is obtained. This result suggests the employment of SBD in the development of quantitative procedures. For this aim, mixtures of different proteins of known molarity were analyzed, showing a good relationship between molarity and intensity ratios. This behaviour was also observed in the case of proteins with quite different ionic yields. The power of the developed method for quantitative evaluation was also tested by the measurement of the abundance of IGPP[Oxi]GPP[Oxi]GLMGPP ( m / z 1219) present in the collagen‐α‐5(IV) chain precursor, differently expressed in urines from healthy subjects and diabetic‐nephropathic patients, confirming its overexpression in the presence of nephropathy. The data obtained indicate that SBD is a particularly effective method for quantitative analysis also in biological fluids of interest. Copyright © 2011 John Wiley & Sons, Ltd.