Direct injection mass spectrometry

Biasoli F, Yeretzian C, Mark TD, et al. Direct injection mass spectrometry adds the time-dimension to (B)VOC analysis. Trends Anal Chem. 2011 30 1003-17. 

Two-dimensional Analysis of Variance Association of Analytical Communities Correlation Spectroscopy Direct Injection Mass Spectrometry Degree of Polymerisation European Food Safety Authority... 

DIMS (Direct Injection Mass Spectrometry) or FIE-MS (Flow Injection Electrospray-MS)... 

The method for chloroacetanilide soil metabolites in water determines concentrations of ethanesulfonic acid (ESA) and oxanilic acid (OXA) metabolites of alachlor, acetochlor, and metolachlor in surface water and groundwater samples by direct aqueous injection LC/MS/MS. After injection, compounds are separated by reversed-phase HPLC and introduced into the mass spectrometer with a TurboIonSpray atmospheric pressure ionization (API) interface. Using direct aqueous injection without prior SPE and/or concentration minimizes losses and greatly simplifies the analytical procedure. Standard addition experiments can be used to check for matrix effects. With multiple-reaction monitoring in the negative electrospray ionization mode, LC/MS/MS provides superior specificity and sensitivity compared with conventional liquid chromatography/mass spectrometry (LC/MS) or liquid chromatography/ultraviolet detection (LC/UV), and the need for a confirmatory method is eliminated. In summary,... 

Specifically for triazines in water, multi-residue methods incorporating SPE and LC/MS/MS will soon be available that are capable of measuring numerous parent compounds and all their relevant degradates (including the hydroxytriazines) in one analysis. Continued increases in liquid chromatography/atmospheric pressure ionization tandem mass spectrometry (LC/API-MS/MS) sensitivity will lead to methods requiring no aqueous sample preparation at all, and portions of water samples will be injected directly into the LC column. The use of SPE and GC or LC coupled with MS and MS/MS systems will also be applied routinely to the analysis of more complex sample matrices such as soil and crop and animal tissues. However, the analyte(s) must first be removed from the sample matrix, and additional research is needed to develop more efficient extraction procedures. Increased selectivity during extraction also simplifies the sample purification requirements prior to injection. Certainly, miniaturization of all aspects of the analysis (sample extraction, purification, and instrumentation) will continue, and some of this may involve SEE, subcritical and microwave extraction, sonication, others or even combinations of these techniques for the initial isolation of the analyte(s) from the bulk of the sample matrix. 

Becker JS, Dietze H-J, McClean JA, Montaser A (1999) Ultratrace and isotope analysis of long-hved radionuclides by inductively coupled plasma quadrupole mass spectrometry using a direct injection high efficiency nebulizer. Anal Chem 71 3077-3984... 

Smith and Udseth [154] first described SFE-MS in 1983. Direct fluid injection (DFT) mass spectrometry (DFT-MS, DFI-MS/MS) utilises supercritical fluids for solvation and transfer of materials to a mass-spectrometer chemical ionisation (Cl) source. Extraction with scC02 is compatible with a variety of Cl reagents, which allow a sensitive and selective means for ionising the solute classes of interest. If the interfering effects of the sample matrix cannot be overcome by selective ionisation, techniques based on tandem mass spectrometry can be used [7]. In these cases, a cheaper and more attractive alternative is often to perform some form of chromatography between extraction and detection. In SFE-MS, on-line fractionation using pressure can be used to control SCF solubility to a limited extent. The main features of on-line SFE-MS are summarised in Table 7.20. It appears that the direct introduction into a mass spectrometer of analytes dissolved in supercritical fluids without on-line chromatography has not actively been pursued. 

SFE-GC-MS is particularly useful for (semi)volatile analysis of thermo-labile compounds, which degrade at the higher temperatures used for HS-GC-MS. Vreuls et al. [303] have reported in-vial liquid-liquid extraction with subsequent large-volume on-column injection into GC-MS for the determination of organics in water samples. Automated in-vial LLE-GC-MS requires no sample preparation steps such as filtration or solvent evaporation. On-line SPE-GC-MS has been reported [304], Smart et al. [305] used thermal extraction-gas chromatography-ion trap mass spectrometry (TE-GC-MS) for direct analysis of TLC spots. Scraped-off material was gradually heated, and the analytes were thermally extracted. This thermal desorption method is milder than laser desorption, and allows analysis without extensive decomposition. 

Two variations on the analysis of PCR products by ESI mass spectrometry have emerged (1) direct-injection MS and tandem mass spectrometry (MS-MS) and (2) liquid chromatography-mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS/MS). In the former approach, the sample is cleaned manually, and as noted above, the cleanup is performed as simply and rapidly as possible. In the latter approach, the cleanup is done automatically... 

Kaderbhai, N. N. Broadhurst, D. I. Ellis, D. I. Goodacre, R. Kell, D. B. Functional genomics via metabolic footprinting monitoring metabolite secretion by Escherichia coli tryptophan metabolism mutants using FT-IR and direct injection electrospray mass spectrometry. Compar. Func. Genomics 2003, 4, 376-391. 

Van der Hoeven, R.A. et al. 1997. Liquid chromatography/mass spectrometry with on-line solid-phase extraction by a restricted-access C18 precolumn for direct plasma and urine injection. J. Chromatosr. A. 762 193-200. 

Grant R.P., Cameron C., and Mackenzie-McMurter S., 2002. Generic serial and parallel online direct injection using turbulent flow liquid chromatography/tandem mass spectrometry. Rapid Commun Mass Spectrom 16 1785. 

Huang M.Q. et al., 2006. Increased productivity in quantitative bioanalysis using a monohth column coupled with high-flow direct-injection hquid chromatography/tandem mass spectrometry. Rapid Commun Mass Spectrom 20 1709. 

Jemal M., Xia Y., and Whigan D.B., 1998. The use of high-flow high performance liquid chromatography coupled with positive and negative ion electrospray tandem mass spectrometry for quantitative bioanalysis via direct injection of the plasma/serum samples. Rapid Commun Mass Spectrom 12 1389. 

Jemal M. et al., 1999. A versatile system of high-flow high performance hquid chromatography with tadem mass spectrometry for rapid direct-injection analysis of plasma samples for quantitation of a /1-lactam drug candidate and its open-ring biotransformation product. Rapid Commun Mass Spectrom 13 1462. 

Xia Y. et al., 2000. Ternary-column system for high-throughput direct-injection bioanalysis by liquid chroma-tography/tadem mass spectrometry. Rapid Commun Mass Spectrom 14 105. 

Zeng W. et al., 2003b. A direct injection high-throughput liquid chromatography tandem mass spectrometry method for the determination of orally active ajSj antagonist in huma urine and dialysatc. Rapid Commun Mass Spectrom 17 2475. 

R.D. Smith and H.R. Udseth, Mass spectrometry with direct supercritical fluid injection, Anal. Chem., 55 (1983) 2266-2272. 

KoUroser M, Schober C. 2002. Direct-injection high performance liquid chromatography ion trap mass spectrometry for the quantitative determination of olanzapine, clozapine and N-desmethylclozapine in human plasma. Rapid Com-mun Mass Spectrom 16(13) 1266-1272. 

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