Preconcentration and determination of phenylalanine in some pharmaceutical and food samples by cloud point extraction coupling with UV-Visible spectrophotometry

Phenylalanine (Phe) is an essential amino acid, which is necessary for infants’ growth and nitrogen equilibrium in adults. However, phenylalanine’s accumulation could cause neurological damages which are the results of deficiency in phenylalanine hydroxylase enzyme, considered as the major enzyme for its metabolism. (1)This enzyme typically begins the procedure of parsing of phenylalanine amino acid molecules which is essential for protein synthesis in the body mutations in the phenylalanine hydroxylase gene will cause a disease called phenylketonuria (PKU).In this work,(2) cloud point extraction in combination with UV-visible spectrophotometry, was used for the extraction of Phenylalanine from some pharmaceuticals and dietary drinks. Lauryl alcohol, 7 ethylene oxide (LAE 7) was used as surfactant for separation and preconcentration of Phenylalanine from sample solutions. Some important parameters such as surfactant concentration, extraction time, temperature and pH were investigated and optimized in order to maximize the extraction efficiency. It was observed that the maximum efficiency of phenylalanine extraction was obtained with 20% (V / V) surfactant LAE 7, 30 minutes at 60 ° C and pH 8.under optimized conditions, the calibration range for L-Ph 10-1000 mg / L-1 with a detection limit of 0.1 mg / L and precision as a standard deviation in the range of 0.4-0.9% .This method has been successfully used to determine phenylalanine in real samples, including colchicine1, ciprofloxacin 500 and Co-Trimoxazole 400/80 tablets and dietary drinks.