------Jou. Raf. Sci., Vol. 20, No.4 pp 69- 81, 2009------ 69 Spectrophotometric Determination of Phenylephrine Hydrochloride by Coupling with Diazotized 2- Aminobenzothiazole Nabeel S. Othman Noha Th. Abdul Fatah Department of Chemistry College of Science Mosul University (Received 17 / 6 / 2009 ; Accepted 5 / 10 / 2009) ABSTRACT A spectrophotometric method for determination of microgram amounts of phenylephrine-HCl(PE) has been proposed. The method is based on coupling of phenylephrine-HCl with diazotized 2-aminobenzothiazole in alkaline medium. The molar absorptivity of the formed dye is 6.620×10 3 l.mol -1 . cm -1 at λ max 510 nm and Beer ' s law obeyed within in the range of 10-250 μg of phenylephrine-HCl /25 ml (0.4 – 10 ppm). The colour reaction was highly stable and did not show a significant change in absorbance(within acceptable analytical error) up to 48 h with a relative error +0.31 to +1.07% and a relative standard deviation of ±0.95 to ±3.09%, depending on concentration level. The method has been applied successfully to the determination of phenylephrine-HCl in pharmaceutical preparation (nose drop) . Keywords: phenylephrine;2-aminobenzothiazole;diazo-coupling; spectrophotometry ــــــــــــــــــــــــــــــــــــــــ ــــــ ــــــــــ ﺍﻟﻤﺅﺯﻭﺕ ﺍﻟﻌﺎﻤل ﻤﻊ ﺒﺎﻻﻗﺘﺭﺍﻥ ﻫﻴﺩﺭﻭﻜﻠﻭﺭﺍﻴﺩ ﺍﻓﺭﻴﻥ ﻟﻠﻔﻨﻴل ﺍﻟﻁﻴﻔﻲ ﺍﻟﺘﻘﺩﻴﺭ2 - ﺍﻤﻴﻨﻭﺒﻨﺯﻭﺜﺎﻴﺯﻭل ﺍﻟﻤﻠﺨﺹ ﻁﺭﻴﻘﺔ ﺍﻗﺘﺭﺍﺡ ﺘﻡ ﻁﻴﻔﻴﻪ ﺍﻟﻔﻨﻴ ﻤﻥ ﺍﻟﺼﻐﺭ ﻓﻲ ﻤﺘﻨﺎﻫﻴﺔ ﻜﻤﻴﺎﺕ ﻟﺘﻘﺩﻴﺭ ل ﻫﻴﺩﺭﻭﻜﻠﻭﺭﻴﺩ ﺍﻓﺭﻴﻥ. ﺘﻌﺘﻤﺩ ﺍﻟﻁﺭﻴﻘﺔ ﻋﻠﻰ ﺍﻻ ﺍﻟﻤﺅﺯﻭﺕ ﺍﻟﻌﺎﻤل ﻤﻊ ﻗﺘﺭﺍﻥ2 - ﺍﻟﻘﺎﻋﺩﻱ ﺍﻟﻭﺴﻁ ﻓﻲ ﺍﻤﻴﻨﻭﺒﻨﺯﻭﺜﺎﻴﺯﻭل. ﺒﻠﻐﺕ ﻤﻌﺎﻤل ﻗﻴﻤﺔ ﺍﻟﻤﻭﻻﺭﻱ ﺍﻻﻤﺘﺼﺎﺹ ﺍﻟﻤﺘﻜﻭﻨﺔ ﻟﻠﺼﺒﻐﺔ6.620 × 10 3 ﻟﺘﺭ. ﻤﻭل - 1 . ﺴﻡ - 1 ﺍﻟﻤﻭﺠﻲ ﺍﻟﻁﻭل ﻋﻨﺩ ﺍﻷﻋﻅﻡ510 ﻨﺎﻨﻭﻤﻴﺘﺭ. ﻭﺘ ﺘﺒﻊ ﺍﻟﻁﺭﻴﻘﻪ ﻤﻥ ﺍﻟﺘﺭﺍﻜﻴﺯ ﻤﺩﻯ ﻓﻲ ﺒﻴﺭ ﻗﺎﻨﻭﻥ10 - 250 ﻤﺎﻴﻜﺭﻭﻏﺭﺍﻡ/ 25 ﻤل) 0.4 - 10 ﺠﺯﺀ/ ﻤﻠﻴﻭﻥ.( ﺘﻐ ﻴﻭﺠﺩ ﻭﻻ ﻋﺎﻟﻴﺔ ﺒﺎﺴﺘﻘﺭﺍﺭﻴﺔ ﺍﻟﻠﻭﻨﻲ ﺍﻟﺘﻔﺎﻋل ﻴﻤﺘﺎﺯ ﻴ ﺍﻻﻤﺘﺼﺎﺼﻴﺔ ﻓﻲ ﻤﻠﺤﻭﻅ ﻴﺭ) ﺍﻟﺨﻁﺄ ﻀﻤﻥ ﺍﻟﻤﺴﻤﻭﺡ( ﻋﻥ ﻻﺘﻘل ﻟﻤﺩﺓ48 ﺴﺎﻋﺔ ﻭﺒﺨﻁﺄ ﻨﺴﺒﻲ ﻴ ﺒﻴﻥ ﺘﺭﺍﻭﺡ0.31 ﻭ%1.07 ﻗﻴﺎﺴﻲ ﻭﺍﻨﺤﺭﺍﻑ ﺒﻴﻥ ﻨﺴﺒﻲ ±0.95 ﻭ% ±3.09 ﺍﻟﺘﺭﻜﻴﺯ ﻤﺴﺘﻭﻯ ﻋﻠﻰ ﺍﻋﺘﻤﺎﺩﺍ. ﺘﻘﺩ ﻓﻲ ﺒﻨﺠﺎﺡ ﺍﻟﻁﺭﻴﻘﺔ ﺘﻁﺒﻴﻕ ﺘﻡ ﺍﻟ ﻴﺭ ﺍﻓﺭﻴﻥ ﻔﻨﻴل ﺍﻟﺼﻴﺩﻻﻨﻲ ﻤﺴﺘﺤﻀﺭﻩ ﻓﻲ ﻫﻴﺩﺭﻭﻜﻠﻭﺭﻴﺩ) ﻗﻁﺭﺓ ﺍﻷﻨﻑ( . ــــــــــــــــــــــــــــــــــــــــــــــــــــ PDF created with pdfFactory Pro trial version www.pdffactory.com