Thebaine estimation

The first scheme for the separation of the six chief alkaloids of opium, VIZ., morphine, codeine, thebaine, papaverine, narcotine and narceine, is probably that of Plugge. Much later Kljatschkina investigated for each of these six bases the properties by means of which isolation and estimation could probably be effected and, on the basis of the results, devised a plan for such analyses. More recently Anneler has published a detailed account of a scheme with the same objective. l Attention had already been given to complex, systematic analyses of this kind, in connection with examination of the mixtures of opium alkaloids, which have long been in use in medicine in these at first only morphine and other alkaloids were determined, but in the more recent schemes provision is made for the estimation of each alkaloid. ... 

The estimation of thebaine in the analysis of opium is described by Klyachkina [55] and Anneler [56], The alkaloid has been estimated in opium residues by condensation with benzoquinone, isolation of the very sparingly soluble adduct, and iodimetric titration of this in chloroform solution. This method is reported to be accurate to 0-5 per cent., provided resins, dyeing substances, and phenolic alkaloids are first removed [57]. Thebaine can also be estimated as its silicotungstate [53] or salicylate [54]. 

A review of the cultivation of Papaver somniferum, and of its improvement and its utilization for medical purposes, has been published/ A method for the quantitative estimation of thebaine in P. bracteatum has been described and a study of the thebaine content of several strains of this poppy has been made. The occurrence of oripavine in P. orientale and of salutaridine in P. brac-teatum and P. lasiothrix has been reported. 

HPLC Analysis. One pi of the aliquot, filtered through a Millipore filter (pore size 0.45 pm) is injected into the LC system. Morphine, codeine, thebaine, papaverine, and narcotine are eluted at the retention times of 12.16, 16.20, 21.09, 25.64, and 29.16min, respectively. Alkaloid percentage is then estimated with the help of linear calibration curves of these alkaloids, obtained by plotting peak area against the quantity of alkaloid injected. Recovery of these alkaloids ranges from 95-100%. 

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