Article Writing Homework Help

You will prepare and submit a term paper on FORENSIC CHEMISTRY: THIN LAYER CHROMATOGRAPHY (TLC). Your paper should be a minimum of 1250 words in length. In this experiment, two different drugs were used to demonstrate the separation mechanism of TLC. Cocaine and benzoylecgonine are drug substances with almost the same chemical structure. Their only difference is the ester functional group for cocaine, while carboxylic functional group for benzoylecgonine (Figure 1). The migration of the drugs were Figure 1. Chemical structure of Cocaine and Benzoylecgonine (Borges et al 2003) compared using a methanol-ammonium hydroxide developing solvent. Potassium iodoplatinate and UV 254 were used to visualise the spots. The Rf value provides information for the spots seen on the TLC plate. The Rf value is calculated as the ratio of the distance travelled by the spot with the distance travelled by the solvent. Rf values are expressed as decimals, and values should not exceed 1.0 (Thin-Layer Chromatography, n.d.). Rf values are expressed in two significant digits due to experimental uncertainties in their measurement (Reich and Schibli 2007). Method A silica gel TLC plate was used for this experiment. A line was drawn at the top and bottom part of the plate. The plate was divided to three, using a pencil to mark the position where the solutions were spotted. The solutions used were methanol (MeOH), cocaine (1 mg/mL in MeOH) and benzoylecgonine solution (1 mg/mL in MeOH).