Investigation into factors affecting precision in ion trap mass spectrometry using different scan directions and axial modulation potential amplitudes

2004 ◽  
Vol 39 (11) ◽  
pp. 1295-1304 ◽  
Author(s):  
G. Dobson ◽  
J. Murrell ◽  
D. Despeyroux ◽  
F. Wind ◽  
J.-C. Tabet
2004 ◽  
Vol 18 (3) ◽  
pp. 441-451
Author(s):  
Melissa D. Zolodz ◽  
Karl V. Wood

Proteomic analysis is becoming a popular field in science. Analysis of protein modifications is useful in deciphering cellular functions and errors in pathways that can result in disease. There has been increased interest in the phosphotyrosine proteome. Due to the difficulty in finding the location of the tyrosine phosphorylation site in the tyrosine phosphorylated peptide or even to verify that the parent protein is a phosphotyrosyl‒protein, new analytical tools are being developed. The phosphotyrosine immonium ion can be produced via skimmer CID for detection via ion trap mass spectrometry and is a useful marker for the indication of the presence of a phosphotyrosine residue. Skimmer CID analysis can also be used to differentiate phosphotyrosine‒containing peptides from other phosphorylated peptides. In this study, phosphotyrosine‒containing peptides were analyzed by skimmer CID in an ion trap mass spectrometer. The factors affecting the signal abundance of the phosphotyrosine immonium ion were investigated.


2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Lily M.G. Panggabean ◽  
Abdullah Rasyid ◽  
Zarrah Duniani ◽  
Yana Meliana ◽  
Indah Kurniasih

Trigliceride or triacylglicerol (TAG) composition in crude oil of sixteen strain of marine diatom has been detected by spectra analyses on an Electrospray - Ion Trap – Mass Spectrometry (ESI-IT-MS) HCT Bruker-Daltonic GmbH instrument with AgNO3 used as coordination ionization agent. Biomass samples of each microalga strain were taken from early and late stationary cultures in f/2 enriched seawater and algal oils were extracted according to Bligh and Dyer. Results from spectra analysis showed that P-Pt-P (C16:0-C16:1-C16:0) were distinguished in TAG from diatom strains Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.1, Thalasiossira sp.2, Thalasiossira sp.3, Navicula sp. 1, Navicula sp. 2, Navicula sp. 3, Navicula sp. 4, Nitzschia sp. 2 and Amphora sp. In contrast, TAGs in Melosira sp. included P-P-P (C16:0-C16:0-C16:0) and P-P-O (C16:0-C16:0-C18:1) were identified. TAGs from Chaetoceros sp. were the most varies among samples, i.e. P-Pt-P (C16:0-C16:1-C16:0), A-P-M (C20:4-C16:0-C14:0), P-Pt-Lt (C16:0-C16:1-C18:3), P-Pt-A (C16:0-C16:1-C20:4), D-P-P (C22:6-C16:0-C16:0), A-Ln-P (C20:4-C18:2-C16:0). Various TAGs were also detected in Nitzschia sp.2, i.e. P-Pt-M (C16:0-C16:1-C14:0), P-Pt-P (C16:0-C16:1-C16:0), P-Pt-S (C16:0-C16:1-C18:0), P-Pt-A (C16:0-C16:1-C20:4). TAGs composition in Skeletonema strains that similar to those in Nitzschia sp.1 has longer carbon, i.e. P-P-O (C16:0-C16:0-C18:1), P-O-O (C16:0-C18:1-C18:1) and O-O-O (C18:1-C18:1-C18:1). TAGs with longer carbon chain and more double bond including highly unsaturated fatty acid C20:4 were increased with culture age in diatoms Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.2, Navicula sp.1 and Nitzschia sp. 2.Keywords: diatom, TAG, ESI-IT-MS, f/2, early and late stationary


2013 ◽  
Vol 33 (10) ◽  
pp. 1108-1115
Author(s):  
Gao FANG ◽  
Peng ZHANG ◽  
Xiao-lan YE ◽  
Xia ZHU ◽  
Xin ZHAO ◽  
...  

Author(s):  
Lisa A. Marzilli ◽  
John P. Barry ◽  
Todd Sells ◽  
Say-Jong Law ◽  
Paul Vouros ◽  
...  

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