Supercritical Fluid Chromatography-Mass Spectrometry SFC-MS

Van Leuken and co-workers [45] have discussed the optimisation of capillary SFC-MS using a standard direct introduction technique capillary interface for the determination of additives in polymers. 

The technique has also been applied to the determination of oligomers in PET [46, 47]. 

Biicherl and co-workers [48] has described an integral restrictive interface with jet separation for coupling capillary column SFC with carbon dioxide mobile phase with high resolution mass spectrometry. 

Fatty acids esters and polymer additive with a wide range of masses could be determined. An FID was used in parallel with the mass spectrometer. 

Klesper, A.H. Corwin and D.S. Turner, Journal of Organic Chemistry, 1962, 

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Supercritical fluid chromatography-mass spectrometry is closely related to HPLC-MS except that SFC is normal phase and HPLC tends to be used in reversed phase mode. In SFC-MS, the mass spectrometer is used in atmospheric pressure ionization (APCI) mode, where there is little fragmentation and the user generally sees a. M + lorM—1 peak (M = molecular weight) is generally prevalent. 

Supercritical fluid chromatography-mass spectrometry has been practiced for many years (12-18,50). The mechanical interface between SFC and MS is now very simple, as shown in Fig. 13. A small fraction of the total flow is split off using a tee mounted either just upstream or just downstream of the... 

SFC/MS. supercritical fluid chromatography and mass spectrometry used as a combined technique SID. surface-induced dissociation (or decomposition)... 

Figure 15 Supercritical fluid chromatography inductively coupled plasma mass spectrometry (SFC-ICP-MS) instrument diagram showing a SFC-ICP interface. (From Ref. 116.)...

The choice of the most suitable instrumental technique depends on several factors, such as the physical-chemical characteristics of analytes, the detection limits required, the level and type of interferences, the resolution needed, the identification power required, the accuracy and the precision of the quantitative determination, the availability of instrumentation and finally the cost and the time necessary per each determination. Moreover, extraction and clean-up procedures have to be suitably matched with instrumental analysis. GC coupled with Electron Capture Detection (ECD) or Mass Spectrometry (MS) has been widely applied for the determination of PCBs in organic extracts of environmental samples. In few cases the instrumentation includes the extraction step, such as an SEE system coupled with Supercritical Fluid Chromatography (SFC) or with GC (40). 

A number of less commonly used analytical techniques are available for determining PAHs. These include synchronous luminescence spectroscopy (SLS), resonant (R)/nonresonant (NR)-synchronous scan luminescence (SSL) spectrometry, room temperature phosphorescence (RTP), ultraviolet-resonance Raman spectroscopy (UV-RRS), x-ray excited optical luminescence spectroscopy (XEOL), laser-induced molecular fluorescence (LIMP), supersonic jet/laser induced fluorescence (SSJ/LIF), low- temperature fluorescence spectroscopy (LTFS), high-resolution low-temperature spectrofluorometry, low-temperature molecular luminescence spectrometry (LT-MLS), and supersonic jet spectroscopy/capillary supercritical fluid chromatography (SJS/SFC) Asher 1984 Garrigues and Ewald 1987 Goates et al. 1989 Jones et al. 1988 Lai et al. 1990 Lamotte et al. 1985 Lin et al. 1991 Popl et al. 1975 Richardson and Ando 1977 Saber et al. 1991 Vo-Dinh et al. 1984 Vo- Dinh and Abbott 1984 Vo-Dinh 1981 Woo et al. 1980). More recent methods for the determination of PAHs in environmental samples include GC-MS with stable isotope dilution calibration (Bushby et al. 1993), capillary electrophoresis with UV-laser excited fluorescence detection (Nie et al. 1993), and laser desorption laser photoionization time-of-flight mass spectrometry of direct determination of PAH in solid waste matrices (Dale et al. 1993). 

Matsumoto K, Nagata S, Hattori H, Tsuge S. Development of directly coupled supercritical fluid chromatography with packed capillary-mass spectrometry with atmospheric pressure chemical ionization. J Chromatogr 1992 605 87-94. Morgan DG, Norwood DL, Fisher DL, Moseley MA III. Directly coupled packed column SFC with APCI/MS. Poster and abstract presented at American Society for Mass Spectrometry. Portland, OR, 1996... 

Sample inlets can also be interfaces that allow the effluents of a variety of powerful separation techniques to enter the ion soimce at a rate that allows for vaporisation to take place. Hence, acronyms such as GC-MS, LC-MS, SFC-MS, etc., relating to gas chromatography, hquid chromatography, supercritical fluid chromatography, etc. coupled to mass spectrometry are now well estabhshed in the jargon of the anal5d ical community as these techniques have been widely accepted and they can be interfaced to any t5q)e of modern mass analyser. 

The coupling of supercritical fluid chromatography (SFC) with mass spectrometry (MS) seems to be easier... 

Hsieh et al. (2006a) demonstrated the use of packed-column supercritical fluid chromatography (SFC) combined with atmospheric pressure chemical ionization (APCI)—tandem mass spectrometry (MS/MS) for the analysis of metabolic stability samples. For the SFC step, the mobile phase is liquid carbon dioxide with some organic modifiers added to adjust the retention time of the analytes. In this report, the primary organic modifier was methanol, and the authors described how the percentage of methanol in the mobile phase varied the retention of the analytes and affected the relative response of the test compounds in the APCI source. The authors also demonstrated that the results obtained by the SFC—APCI—MS/MS assay were equivalent to those obtained by a conventional HPLC—APCI—MS/MS assay, as shown in Figure 12.3. 

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