PRACTICAL REPORT ON THE ISOLATION AND IDENTIFICATION OF CODEINE AND PARACETAMOL Essay

Codeine or methyl morphine, an alkaloid, was for the first time isolated in 1832 from raw opium. It concentration ranges from 0.2% to 0.8%. Mostly used for its analgesic, anti-tussive and anti-diarrheal capabilities (Tremlett, Anderson and Wolf, 2010). Paracetamol withal known as acetaminophen (n-acetyl-p-aminophenol, APAP) on the other hand, is a useful non- steroidal anti- inflammatory drug (NSAID). It is commonly used in the management of pain and fever in a variety of patients (Kamberi, et al., 2004).Fig 1 CodeineNCBI, 2009 Fig 2 AcetaminophenNCBI, 2009 One of the technique involved in the extraction of codeine and paracetamol from its matrix, is the root extraction otherwise known as liquid liquid extraction. This process entails the use of two immiscible liquids usually put out and water in dissolving the sample for two distinctive layers to form after the mixture had been thoroughly agitate together (Rubinson and Rubinson, 1998). Separating the components of the extrac t, is done through the use of adulterate Layer Chromatography. It is one of the standard procedures used in some(prenominal) forensic laboratory when analysizing unknown drugs or mixtures (Howlett and Steiner, 2011). Separation of the mixtures occur based on the pH, polarity of its components, solvent and the rationalize layer stationary physical body (Howlett and Steiner, 2011).METHODSThe finely divided sample was dissolved in 20ml of di calmed water. This was thence basified with NaOH solution to pH 12 using litmus paper. The resulting solution was later filtered. 1.0ml of chloroform was pipetted into the filtrate. afterwards shaken and combined, two distinctive layers was detect. The bottom layer was extracted thrice using a micro- pipette. On a thin chromatography plate, five spots were placed ( as shown in remand 2) and theplate was readyed using chloroform/methanol. This was later visualized with dragendorffs reagent under the UV light. All separated components were o bserved, identified and recorded. RESULTSTable of observed pHSOLUTIONInitial pHFinal pHBasified sample1012 dining table 1Table of Retention factor (RF value)Rf = Distance traveled by the bone marrow (cm) Distance travelled by the solvent (cm) SUBSTANCEDistance travelled by aggregate (cm)Distance travelled by Solvent (cm)Retention factor value (Rf) Chloroform extract3.04.00.75Codeine positive examine3.04.00.75Paracetamol positive control4.04.01.00Chloroform (negative control) 3.54.00.86Diluted sample4.04.01.00TABLE 2DIAGRAMFig 3 The Developed Chromatographic Plate.DISCUSSIONRunning the chloroform extracts and cut sample together with two positive controls and a negative control on a virtuoso chromatographic plate simultaneously, the store factor(Rf) of five different samples were determined. The RF value of the chloroform extract(0.75) tallied with that of the codeine positive control and that of diluted sample(1.00) with the paracetamol positive control. This tentatively show s that, codeine and paracetamol were present in the sample. The solvent front(i.e distance travelled by the meld solvents) is 4cm, this is quite close to the distances covered by all separated components(between 3 3.5cm), which makes the retention factors, not a true representative of their actual set. It was later discovered that, this is due to not allowing thechromatographic plate to develop for a longer period of time in the solvent tank. The solvent front also dehydrated up quickly when the plate is taken out., making drawing a line at that orient quite difficult. Fortunately, this was overcome by the use of visualizing spray and UV lamp. Solvent extraction(liquid-liquid), involved selective reason of components of a substance in microgram to gram quantities between two immiscible liquid manakin its separation and selectivity is based on solubility differences and pH control respectively (Fifield and Kealey, 1995).This was observed when chloroform was added to the basifi ed filtrate. After vigorous shaking and settling down, chloroform being more dense, composed the bottom layer, with the aqueous phase up. Liquid-liquid extraction often involved high volume of organic solvents and poor resolution of mixtures of organic materials (Fifield and Kealey, 1995). deoxidize Layer Chromatography is usually employed in the qualitative analysis of mixtures of non-volatile compounds like pharmaceuticals (Skoog, et al., 2000). TLC can also be used to confirm the identity of an unknown sample ( Lewis and Evans, 2011). Dissolution of the codeine and paracetamol tablet in distilled water without weighing, shows that, TLC was never designed for semi- quantitative analysis. This is due to difficulties in reproducibly applying aliquots of the mixture to the plate and then recovering all of the separated components from the plate (Skoog, et al., 2000). CONCLUSION Using the Rf values obtained in the table 2 above and the visual indicator reaction with the substances un der the UV light, codeine was extracted to a high spirit level during the solvent extraction, tentatively identified by TLC (due to its positive control having the same Rf values with the chloroform extract(0.75) and both were the only one that were seen under the UV light) while paracetamol was extracted to a low floor (due to its positive control having the same Rf with the diluted sample). Multiple compounds can sh atomic number 18 the same retention factor(Rf) or produce similar chromophores when sprayed with detection reagents (Howlett and Steiner, 2011). The study by Lewis and Evans( 2011) shows that if a spot from an unknown substance is developed on a TLC plate together with a spot from a substance that is suspected to be the unknown, and the two substance are found to have the same Rf value, they are probably the same substance.FUTURE SUGGESTIONS AND RECOMMENDATIONS Due to the limitation that is associated with using TLC to exactly identify a given sample, minimum standar ds for drug testing and reporting in the forensic community are recommended by the Scientific Working Group for the Analysis of seized drugs (SWGDRUG) (Howlett and Steiner, 2011). In order for a drug identification to be confirmed to SWGDRUG specification, additional tests must includes, Infrared spectroscopy and GC-MS (Howlett and Steiner, 2011).REFERENCESFifield, F. W. and Kealey, D. 1995. Principles and Practice of Analytical chemistry. (4th ed) Glasgow, Blackie Academic and professional. Howlett, S. E. and Steiner, R. R. 2011. Validation of Thin Layer Chromatography with AccuTOF-DART Detection for Forensic Drug Analysis*. Forensic Sciences e-journal 56 (5), pp. 12611267. available through Anglia Ruskin University program library website http//libweb.anglia.ac.uk Accessed on 11 March 2014. Kamberi, M., Riley, C. M., Huang, C. C. and Xiaoyan, M, 2004. A validated, sensitive HPLC method for the determination of trace impurities in acetaminophen drug substance. Pharmaceutical and Biomedical Analysis e-journal 34 (1), pp. 123128. Available through Anglia Ruskin University Library website http//libweb.anglia.ac.uk Accessed on 18 March 2014. Lewis, R. and Evans, W. 2011. Chemistry. 4th ed. Hampshire, Palgrave Macmillan. NCBI, 2009. National Library of Medicine. online Available at http//www.ncbi.nlm.nih.gov/pccompound Accessed 7 April, 2014. Rubinson, J. F. and Rubinson, K. A. 1998. Contemporary chemical analysis. speed Saddle River, NJ, Prentice Hall. Skoog, D., West, D., Holler, F. and Crouch, S. 2000. Analytical Chemistry- An introduction. (7th ed). Boca raton, Thomson Learning Inc. Tremlett, M., Anderson, B. J. and Wolf, A. 2010. Procon debate is codeine a drug that still has a useful role in pediatric practice? Pediatric Anesthesia e-journal 20 (2), pp. 183194. Available through Anglia Ruskin University website http//libweb.anglia.ac.uk Accessed on 29 March 2014.