Chemistry: analytical and immunological testing – Including titration or ph determination
Patent
1993-11-09
1995-11-21
Housel, James C.
Chemistry: analytical and immunological testing
Including titration or ph determination
436 39, 436 41, 436 61, 436100, 436166, G01N 3122
Patent
active
054686440
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a method of spectroscopic investigation of analytes usually (but not necessarily) by infrared or Raman techniques, using organometallic compounds.
Infrared spectroscopy is widely employed for the direct determination of infrared-active analytes. In such work, it has long been observed that vibrating-group frequency shifts occur in infrared spectra depending on internal changes to the analyte molecule and on external changes to the environment of the vibrating group.
An advantage of using certain organometallic compounds, in particular metal carbonyls, in infrared spectroscopic analysis is that the carbonyl stretching frequencies are narrow, intense bands falling at around 2000 cm.sup.-1, which is a part of the spectrum relatively free from interfering absorbances from the commoner solvents. This advantage is exploited according to Jaouen et al's U.S. Pat. No. 4656142, which discloses that oestrogen may be quantitatively determined by binding it to a `designer` carbonyl-containing organometallic compound, removing surplus compound, and, from the intensity of infrared absorption, establishing the quantity of carbonyl--and hence oestrogen--present in the sample.
It is incidentally observed in the experimental plots illustrating the Jaouen patent, confirming an earlier remark above, that carbonyl frequency shifts occur between the `designer` organometallic compound when uncombined in solution and when in the solid, bound to the oestrogen. This observation is not put to any use, indeed it does not rate a mention in the text of the patent.
We have found that the frequency shift and any change of shape of the peak can in fact convey valuable information, not as much (as might be supposed) about the vibrating group as such (carbonyl in that case) nor indeed even about only its immediate environment, but also about the environment of a functional group at a remote part of the organometallic compound. Present-day knowledge does not allow the full implications of a frequency shift or change of peak shape to be determined from first principles, and therefore we correlate an observed shift or change with reference samples.
SUMMARY OF THE INVENTION
Therefore, the present invention is a method of investigating an analyte, comprising presenting an organometallic compound to the analyte, the said compound having a probe group affected by the analyte and linked to a metal-ligand system, the said system comprising at least one infrared/Raman active group, observing the shape(s) and/or wave-number position(s) of the peaks and/or other part(s) of the infrared/Raman spectrum of said system, comparing said shape(s) and/or position(s) with the corresponding shape(s) and/or position(s) in known analytes, and, by interpolation or extrapolation if necessary, determining a characteristic of the analyte.
The said shape(s) may be investigated by Principal Component Analysis, a statistical technique for analysing data, in this case infra-red data, to yield a small number of meaningful Principal Components, each successive Principal Component accounting for as much of the (remaining) variability of the information as possible subject to being uncorrelated with (=mathematically orthogonal to) all the previous Principal Components; each Principal Component may be described by a Score and a Weighting ("Loading"). Thus, the shape of even one peak can be made to reveal significant quantities of information.
Preferably, in the organometallic compound, the linkage between the probe group and the metal-ligand system is made by use of a common organometallic bonding mode so that the probe group is bound as a carbyne, a carbene, .eta..sup..eta. .pi.-complex (where n is preferably from 1 to 7), or a o-bound ligand. Examples of a suitable .eta..sup..eta. .pi.-complex are (where n=the number of carbon atoms .pi.-bonded to the metal) alkene or alkyne (n=2), diene (n=4) or arene (n=6).
The probe group may be selected according to the relevant characteristic being investigated of the analyte, thus for example the probe group
REFERENCES:
patent: 4656142 (1987-04-01), Jaouen et al.
M. Salmain et al. "(N-succinimidyl 4-pentynoate) . . . " Bioconjugate Chem. vol. 2 No. 1, 1991, pp. 13-15.
G. Jaouen et al. "Metal carbonyl fragments . . . " Jour of the Am Chem Soc., vol. 107 No. 16 (16 Aug. 1985), pp. 4778-4780.
F. Le Borgne et al. "Cobalt-carbonyl complexes . . . " Tethedron Letters, vol. 29 No. 44 (1988), pp. 5649-5652.
K. Erdmann et al. "Adsorption of carbonyls on . . . " Chemical Abstracts #216628, vol. 109 No. 24 (12 Dec. 1988), p. 371.
D. M. Adams Spectr., Rept. Conf. Hydrocarbon Res. Group Inst. Petrol., London, 1962, 265-278.
D. M. Adams Chem. Abstr. 1969, 70, 52537v.
S. Cenini et al. Gazz. Chim. Ital. 1972, 102, 141-163.
B. V. Lokshin et al. J. Organomet. Chem. 1972, 37, 331-337.
F. van Meurs et al. J. Organomet. Chem. 1976, 113, 353-359.
J. Korppi-Tommola et al. Can. J. Chem. 1979, 57, 2707-2712.
A. Meyer et al. Organomettalics 1984, 3, 1112-1118.
J. M. Bjerga et al., Anal. Chem. 1990, 62, 226-233.
T. A. Weil et al. Inorg. Chem. 1969, 8, 1002-1004.
S. Cenini et al. Chem. Abstr. 1972, 77, 41003m.
R. J. Klingler et al. Inorg. Chem 1981, 20, 34-40.
S. Tondu et al., J. Chem. Soc., Chem. Commun. 1985, 326-328.
G. Jaouen et al. Pure & Appl. Chem. 1985, 57, 1865-1874.
A. Vessieres et al. Inorg. Chem. 1988, 27, 1850-1852.
A. A. Ismail et al. Clin. Biochem. 1989, 22, 297-299.
I. S. Butter et al. Appl. Spectrosc. 1989, 43, 1497-1498.
M. Savignac et al. J. Chem. Soc. Chem. Commun. 1991, 615-617.
G. Patonay et al. Appl. Spectrosc. 1991 45, 457-461.
C. C. Barraclough et al. J. Chem. Soc. 1961, 2582-2584.
D. A. Brown et al. J. Chem. Soc. 1962, 3849-3854.
E. H. Santos et al. J. Organomet. Chem 1989, 375, 197-201.
Creaser Colin S.
Stephenson George R.
British Technology Group Limited
Housel James C.
Soderquist Arlen
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