Ion tandem

An enzyme-linked immunosorbent assay (eflsa) has been developed for the detection of residues on hands. As Httle as 50 pg of TNT can be detected (126). Liquid chromatography/thermospray negative-ion tandem ms has been successfully used to detect picogram levels of explosives in post-blast debris (127). 

Dieckhaus, C.M. et al. 2005. Negative ion tandem mass spectrometry for the detection of glutathione conjugates. Chem. Res. Toxicol. 18 630. 

ESI-triple-quadrupole MS is one example of the often used term tandem MS (MS-MS), where by definition a precursor ion is mass-selected and typically fragmented by Cl D, followed by mass analysis of the resulting product ions. The technique requires two mass analyzers (in the case above, three are used) in series (or a single mass analyzer that can be used sequentially) to analyze the precursor and product ions. Tandem MS provides structural information by establishing relationships between precursor ions and their fragmentation products. 

Lee HW, Park WS, Kim YW, Cho SH, Kim SS, Seo JH, Lee KT (2006) A rapid and sensitive liquid chromatography/positive ion tandem mass spectrometry method for the determination of cimetropium in human plasma by liquid-liquid extraction. J Mass Spectrom 41 855-860... 

J. Riches, I. Morton, R.W. Read and R.M. Black, The trace analysis of alkyl alkylphosphonic acids in urine using gas chromatography-ion trap negative ion tandem mass spectrometry, 7. Chromatogr. B, accepted for publication. 

Currie, G.J., Kallio, H. 1993. Triacylglycerols of human milk rapid analysis by ammonia negative ion tandem mass spectrometry. Lipids, 28, 217-221. 

Top FAB mass spectrum of a mixture of five peptides. The m/z of the protonated molecular ion (M + H)+ of each of them is observed. Bottom product ion tandem mass spectrum of the (M + H)+ ion with m/z 872, giving the sequence of this peptide alone. The values within the frame are the masses of the various possible fragments for the indicated sequence. 

Acetate esters emitted from a banana, parent-ion tandem mass spectrum, 132f... 

LC Taylor, RL Johnson, L St John-Williams, T Johnson, SY Chang. The use of low-energy collisionally activated dissociation negative-ion tandem mass spectrometry for the characterization of dog and human urinary metabolites of the drug BW 1370U87. Rapid Commun Mass Spectrom 8 265, 1994. 

Verweij A, De Bruyn P, et al. 1993. Liquid chromatographic, thermospray/negative ion, tandem mass spectrometic analysis (Ic/tsp/ms/ms) of some exposives. Forensic Sci. Int. 60 7-13. 

Jackson, A. T., Jennings, K. R., and Scrivens, J. H., Generation of average mass values and end group information of polymers by means of a combination of matrix-assisted laser desorption/ionization-mass spectrometry and liquid secondary ion-tandem mass spectrometry, /. Am. Soc. Mass Spectrom., 8, 76, 1997. 

Kallio, H. and Currie, G. (1993b) Analysis of natural fats and oils by ammonia negative ion tandem mass spectrometry - triacylglycerols and positional distribution of their acyl groups, in CRC Handbook of Chromatography, Analysis of Lipids (eds K. Mukherjee, N. Weber and J. Sherma), CRC Press, Boca Raton, FL, pp. 435-58. 

Zhang, J. Y., Nobes, B.J., Wang, J. and Blair, LA. (1994) Characterization of hydroxyeicosa-tetraenoic acids and hydroxyeicosatetraenoic acid phosphatidylcholines by liquid secondary ion tandem mass spectrometry. Biol Mass Spectrom., 23, 399 05. 

Chace, D., Millington, D. (1994) Neonatal screening for inborn errors of metabohsm by automated hquid secondary ion tandem mass spectrometry. In New Horizons in Neonatal Screening, Proceedings of the 9th International Neonatal Screening Symposium, edited by Farriaux, J., Dhont, J. Amsterdam, The Netherlands Elsevier, pp. 373-377. 

GC-MS analysis is used to confirm the identities of ions in the LSI-MS urine spectrum and show that the excretion of abnormal cholanoids is >20 times normal. In the case of 5 ff-reductase deficiency GC-MS analysis should show that S-oxo-A" bile acids account for >70% of the total urinary bile acid excretion. In the case of sterol 27-hydroxylase deficiency (CTX), GC-MS analysis should indicate that the major cholestane pentols in the urine are 3,7,12,22,25 and 3,7,12,23,25-pentols. (One patient has been described who had familial cholestatic liver disease associated with greatly increased urinary excretion of 5jff-cholestane-3a,7a,12a,24 S,25-pentol [see previous table]). Liquid secondary ion-tandem mass spectrometry (LSI-MS/ MS) is an alternative method to GC-MS and can rapidly confirm the identity of a number of diagnostic ions that are found in the LSI-MS spectrum of urine. These include sulphated and taurine-conjugated abnormal metabolites such as those observed in 3 ff-HSDH deficiency (32.1), 5)9-reductase deficiency (32.2), oxysterol 7a-hydroxylase deficiency (32.4) and peroxisomal disorders [13]. 

Bristow AWT, Webb KS, Lubben AT, Halket J (2004) Reproducible product-ion tandem mass spectra on various liquid chromatography-mass spectrometry instruments for the development of spectral libraries. Rapid Commun Mass Spectrom 18 1447-1454... 

Figure 6 Charge-reversal (positive-ion) tandem mass spectra of (A) CHsCOi and (B) -OCH2CHO. ZAB 2HF mass spectrometer. Argon collision gas pressure adjusted in the first collision cell so that the reduction in the main beam is 10%.

Figure 20.9. Two-dimensional mass spectrometric analysis of GPIns molecular species in a lipid extract of mouse myocardium. The lipid extract of mouse myocardium was prepared by a modified Bligh and Dyer procedure as previously described. Each MS or MS/MS trace of the 2D ESI mass spectrum was acquired by sequentially programmed, customized scans operating under Xcalibur software. For negative-ion tandem mass spectrometry in the precursor-ion (PI) mode, the first quadrupole was scanned in the selected mass range and the second quadrupole was used as a coUision cell while the third quadrupole was fixed to monitor the ion of interest (i.e., either inositol phosphate, glycerophosphate, or a fatty acyl carboxylate fragmented from GPIns molecular species). All mass spectral traces were displayed after being normalized to the base peak in each individual trace.

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