A novel method for quantification of XXXX hemoglobin from dried blood spots by use of tandem mass spectrometry.

@entity1 @entity417 @entity3458 @entity74 @entity2142 @entity2395
Quantification of @entity1 hemoglobin (Hb) is essential for diagnosis of @entity417 , especially for screening for @entity2395 and @entity3458 . The main methods currently used for quantification of Hb, including spectrophotometry, fluorimetry, and electrochemical assays, are all based on the structural integrity of Hb, which could be affected by @entity2142 and degradation. When used for disease screening, whole blood specimens cannot meet requirements for sample collecting, transport, and storage. Here, we report a novel MS-MS method for quantification of Hb from dried blood spots (DBS) by use of a triple-quadrupole mass spectrometer. Proteospecific peptides from a-globin chains were selected after tryptic digestion. The precursor    >    product ion transitions of representative peptides were studied to identify the best choice with regard to sensitivity and chromatographic properties. For quantification, stable isotope-labeled peptides were used as internal standards. The concentration of Hb in each sample was obtained by calculation on the basis of established equations. The precision of the method was within 15  % and accuracy was in the range -7 to 13.0  %. Compared with routine clinical results obtained by use of the automated hematology analyzer (AHA) assay, the correlation, r (2), was >0.993. When used for determination of @entity417 levels the sensitivity of the assay was 95.7  % and specificity 96.5  %. Our new approach for quantification of the concentration of Hb from DBS is feasible, and precision is acceptable. The method could be used for determination of @entity417 levels when screening for @entity74 . Graphical Abstract Quantification of @entity1 hemoglobin from digested dried blood spot samples using tandem mass spectrometry.
