Due to the technology development, the diet habit has completely changed. It accompanied by the metabolite diseases relevant to blood glucose and lipids, which are dependent with the atherosclerosis and cardiovascular disease. In this study, we using matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF/MS) to characterize triglycerides in human plasma. In the other, the glycosylated hemoglobin in human whole blood was detected by liquid electrospray laser desorption ionization (Liquid ELDI/MS).
Triglycerides are energy source (9 kcal/g) in human body, derived from glycerol and three fatty acids. It is a main constituent of vegetable oil and animal fats. In clinical diagnosis, human plasma was mixed with triglyceride Kit to react to the final 520 nm UV-absorbing substance, then the concentration was quantified consistent with the calibration line by UV/Visible spectrometry. By the way, it needed Kit chemicals for one trial. MALDI-TOF/MS is a simple and easy method to operate to detect complex compounds in human plasma, only need to optimize the parameters (solvent collection, sample dilution, matrix selection, sample pretreatment ) to form a homogeneous crystals. The developed ¡§seed layer¡¨ method can reduce the sweet spot effect and cause a lower with-in spot variation (RSD < 20%) compared to ¡§premix¡¨ method (RSD >30%). Combined with statistic software 2D peak distribution, a semi-quantification can be observe of 24 different triglyceride concentration human plasmas.
The level of glycosylated hemoglobin (HbA1c) in whole blood is currently the most important measurement of long-term control of the glycemic state of diabetes. As a result of the interferences of high concentrations of metabolites, proteins and salts in whole blood, tedious sample cleanup procedures must be performed prior to subjecting the sample solutions to conventional LC/MS and MALDI analyses for the detection of HbA1c. Electrospray laser desorption ionization mass spectrometry (ELDI/MS), a two-step ambient ionization technique, has been developed to characterize analytes directly from the liquid sample surface. One drop of the diluted hole blood (1/10, v/v in water) was placed on the stainless steel plate. The sample droplet was irradiated with a pulse laser, the desorbed analytes were post-ionized in an electrospray (ESI) plume (ESI solution: 70% methanol in water, 0.1% acetic acid), and the analyte ions were detected by a ion trap mass analyzer.
Through this study, the protocol for efficiently characterizing HbA1c present in a drop of diluted whole blood with ELDI/MS was established. We successfully detected the ion signal of HbA1c with ELDI/MS. Quantification of the level of HbA1c in the whole blood of diabetic patients was achieved by calculating the ratio of the ion peak area of the glycosylated and non-glycosylated hemoglobin ions. A linear relationship exists for the quantitative results of HbA1c in whole blood of 20 diabetic patients obtained between ELDI/MS and that through conventional spectroscopic measurement.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0830111-163624 |
| Date | 30 August 2011 |
| Creators | Kuo, Shih-chieh |
| Contributors | Po-Chiao Lin, Wei-Lung Tseng, Jen-taie Shiea |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0830111-163624 |
| Rights | user_define, Copyright information available at source archive |
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