کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1194566 1492332 2010 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Detection of saccharides by reactive desorption electrospray ionization (DESI) using modified phenylboronic acids
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Detection of saccharides by reactive desorption electrospray ionization (DESI) using modified phenylboronic acids
چکیده انگلیسی

We have reported previously a method for the detection of sugars via in-situ derivatization with phenylboronic acid PhB(OH)2 using reactive desorption electrospray ionization (DESI, Chen et al., Chem. Commun. (2006) 597–599). The present study describes an improved method that employs modified phenylboronic acids including 3-nitrophenylboronic acid and N-methyl-4-pyridineboronic acid iodide. In contrast to using PhB(OH)2, enhanced sensitivity of using 3-nitrophenylboronic acid was observed due to the stabilization of the resulting boronate ester anion by the electron-withdrawing nitro group and the limit of detections (LODs) for glucose in water using 3-nitrophenylbornic acid and phenylboronic acid were determined to be 0.11 mM and 0.40 mM, respectively. In the case of N-methyl-4-pyridineboronic acid iodide, the corresponding LOD is 6.9 μM and the higher sensitivity obtained is attributed to the efficient ionization of both the reactive DESI reagent and reaction product since the precursor acid with a quaternary ammonium group is pre-charged. In this case, additional important features are found: (i) unlike using phenylboronic acid or 3-nitrophenylbornic acid, the experiment, performed in the positive ion mode, is applicable to neutral and acidic saccharide solutions, facilitating the analysis of biological fluids without the need to adjust pH; (ii) simply by changing the spray solvent from water to acetonitrile, the method can be used for direct glucose analyses of both urine and serum samples via online desalting, due to the low solubility of salts of these biofluids in the sprayed organic solvent; (iii) in comparison with other sugar derivatizing reagents such as the Girard's reagent T, the N-methyl-4-pyridineboronic acid iodide shows higher reactivity in the reactive DESI; and (iv) the ions of saccharide DESI reaction products undergo extensive ring or glycosidic bond cleavage upon CID, a feature that might be useful in the structure elucidation of saccharides. In addition, a variant sample introduction protocol using pipette tips for saccharide solutions was also demonstrated in the reactive DESI experiments, allowing the analysis of multiple samples of a small volume (e.g., 200 nL) in a short period of time (e.g., five samples in 4 min). The method reported in this study with improved sensitivity and high selectivity along with online desalting and high throughput capability could find useful applications in saccharide analysis in complicated biological samples.

A reactive DESI method using a charge-labeled compound as chemical reagent has been developed for the sensitive, selective and fast detection of saccharides and the possibility for online desalting and high throughput analysis has also been demonstrated.Figure optionsDownload high-quality image (187 K)Download as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Mass Spectrometry - Volume 289, Issues 2–3, 15 January 2010, Pages 98–107
نویسندگان
, ,