Chemistry: analytical and immunological testing – Oxygen containing – Carbonyl – ether – aldehyde or ketone containing
Patent
1994-08-02
1996-07-23
Warden, Jill
Chemistry: analytical and immunological testing
Oxygen containing
Carbonyl, ether, aldehyde or ketone containing
436127, 436130, 436166, G01N 3122
Patent
active
055388990
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a method of analysing for an alkyl ketene dimer.
Alkyl ketene dimers are higher analogues of diketene and are of the formula ##STR1##
where each R.sup.1 represents the same or different alkyl group (usually a long chain alkyl group, e.g. C.sub.14 -C.sub.18). Generally the alkyl group is a linear, straight chain group.
Alkyl ketene dimers (AKD) are used in the sizing of paper, for which they are preferred to rosin sizes for certain applications. For a number of applications, it may be desired to analyse for the AKD either qualitatively or quantitatively, e.g. on the sized paper or in the water drained through the wire of a Fourdrinier machine. The most common technique used for the study of AKD sizing is by radioactive tracers. Although this technique permits an accurate determination of AKD size retention in paper, it is limited to use in specialised laboratories. IR and HPLC have been tried for analysis of AKD but they are quite complex and not particularly convenient.
It is therefore an object of the present invention to provide a method of analysing for an alkyl ketene dimer which obviates or mitigates the abovementioned disadvantages.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method of analysing a sample for an alkyl ketene dimer (AKD) comprising treating the sample or extract thereof with a compound having a nitrogen-containing heterocyclic ring, said compound having at least one amino substituent on the ring containing the nitrogen atom, to produce a detectable derivative, and effecting a detection for said derivative.
For preference the derivative is one which absorbs in the visible and/or ultra-violet region of the spectrum. In the case where the derivative is coloured, the appearance of a colour change (upon reaction of the sample or extract with the reagent) demonstrates the presence of AKD in the original sample. Alternatively or additionally the amount of the derivative may be determined spectroscopically so as to provide a quantitative analysis of the amount of AKD present in the original sample.
The heterocyclic ring may optionally be further substituted and may be part of a fused ring system. Preferably the heterocyclic ring is a 6-membered ring and preferably also the amino substituent is an N-alkylamino or N,N-dialkylamino substituent, most preferably having 1 to 4 carbon atoms. The preferred compounds are those having a pyridine ring, most preferably with the amino substituent at the 4-position.
The preferred reagent for use in the invention is of the general formula ##STR2##
in which R.sub.1 and R.sub.2 are the same or different C.sub.1 -C.sub.4 alkyl groups. The heterocyclic ring may include other substituents.
Most preferably the reagent is 4-(N,N-dimethylamino)pyridine (DMAP) which we have found to react with AKD to produce a yellow derivative. Whilst we do not wish to be bound by any theory, we believe that the reaction between the AKD and DMP produces a yellow derivative of the following structure: ##STR3##
We have established that the reaction between AKD and DMAP proceeds quantitatively, and this allows determination of AKD (in the original sample) by visible an/or ultraviolet spectroscopy. In particular, the yellow reaction product of AKD with DMAP has been found to display two absorbance maxima at 450 nm (visible range) and 338 nm (UV range), either of which can be used for the determination of AKD.
The method of the invention may be used for the analysis of AKD in "waste" water from the paper making process, in the "input" water to the process, or on the paper itself. We have established that DMP reacts specifically with AKD and not with hydrolysis products thereof nor with AKD which has reacted with cellulose. The method may also be used to analyse AKD emulsions to test for the extent (if any) to which the AKD has been hydrolysed.
In practising the method of the invention the DMAP (or other reagent, e.g. another amino substituted nitrogen containing heterocycle) should be dis
REFERENCES:
G. Stockelmann et al. Chem. Ber. 1969, 102, 455-458.
N. V. Stepanyuk et al. Chem. Abstr. 1966, 65, 4522g.
J. A. Berson et al, J. Am. Chem. Soc. 1956, 78, 1625-1631.
G. A. Taylor J. Chem. Soc. 1965, 3332-3335.
R. Adam et al. J. Am. Chem. Soc. 1952, 74, 5491-5497.
T. Kato et al. Chem. Pharm. Bull. 1972, 20, 133-141.
T. Kato et al. Chem. Pharm. Bull. 1972, 20, 142-146.
Wilson et al. J. Org. Chem., (1984) 49(4) 722-725 (Abstract Only).
Nudelman et al., Synthesis, (1989) (5) 387-389.
Kato, Chem Pharm. Bull. 28(7) 2129-2135 (1980).
Fresenius Zeitschrift Fur Analytische Chemie vol. 323, No. 5, 1986, Berlin De, pp. 487-489, M. Kapernaum et al. Spectrometric Detection and Determinationof Ketene.
Roberts John C.
Zhou Ya J.
Browning Clifford W.
Soderquist Arlen
The University of Manchester Institute of Science and Technology
Warden Jill
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