Applications Of Matrix Assisted Laser Desorption/Ionization Mass Spectrometry For Bioanalysis

In the field of life analytical chemistry,mass spectrometry is recognized as an important measurement method.In particular,the MALDI method,in which the detection reaches the highest mass region,can be used for development of new drugs and diagnosis of cancer etc.,which is used for structure analysis of proteins and sequence analysis of genes.While this MALDI method is very useful,on the other hand,problems such as poor reproducibility of measurements and difficulties in detection itself for target samples with small ? orders are a problem.These problems occur mainly in the sample preparation process.In other words,it can be said that this is an artificial problem.If anyone can use the MALDI method easily and conveniently,there is also the possibility that the field of mass spectrometry analysis will spread widely.In this research,aiming to whole cell analysis in MALDI-MS,a sample introduction method using inkjet,which is well-known as common image printer,as a sample preparation method for a single cell type sample was provided.However inkjet device itself cannot produce good sample droplet for MALDI-MS detection.By optimizing the sample plate conditions by hydrophobic modification and sample drying speed by humidity controlling,suitable sample droplets were created.Next,aiming to oligonucleotide analysis,a novel matrix material having high surface uniformity was prepared for establishing easy operation of MALDI-MS.Peaks were obtained in many parts of the sample droplet,and measurements without the need for a special technique was established.In addition,the effect was verified by using a porous alumina substrate having a highly ordered nanostructure.Porous alumina with a regular two-dimensional array structure acted as a MALDI plate by depositing metal.In the aluminum vapor deposition substrate which is more likely to cause functions against nitrogen laser,peaks derived from cleavages which could not be detected by other substrates were observed.This suggests that higher energies were supplied to the matrix than when using other substrates,and it is considered that more efficient energy conversion is performed by the detection method using aluminum.