Spectrophotometric Determination of Tetracycline by Coupling with Diazotised 4-Aminoantipyrine in Presence of Cetylpyridinium Chloride

Abstract

A spectrophotometric method for the determination of microgram amounts of tetracycline-HCl(TCH) has been proposed. The method is based on coupling of tetracycline-HCl with diazotized 4-aminoantipyrine in presence of cetylpyridinium chloride in alkaline medium. The molar absorptivity of the formed dye reached to 1.92×10 4 l.mol-1. cm-1 at 537 nm and Beer ' s law is obeyed within the range of 10-300 µg of tetracycline-HCl /10 ml (i.e.1.0-30 ppm). The colour reaction was highly stable, a relative error ranged from-2.5 to + 0.21 % and a relative standard deviation of ± 0.37 to ± 0.73 %, depending on concentration level of tetracycline-HCl. The proposed method has been applied successfully to the determination of tetracycline-HCl in pharmaceutical preparations. ‫ــــــــــــــــــــــــــــــــــــــــــــــــــــ‬ ‫ﺍﻟﻤﺅﺯﻭﺕ‬ ‫ﺍﻟﻌﺎﻤل‬ ‫ﻤﻊ‬ ‫ﺒﺎﻻﻗﺘﺭﺍﻥ‬ ‫ﻟﻠﺘﺘﺭﺃﺴﺎﻴﻜﻠﻴﻥ‬ ‫ﺍﻟﻁﻴﻔﻲ‬ ‫ﺍﻟﺘﻘﺩﻴﺭ‬ 4-‫ﺒﻭﺠﻭﺩ‬ ‫ﺒﺎﻴﺭﻴﻥ‬ ‫ﺍﻨﺘﻲ‬ ‫ﺍﻤﻴﻨﻭ‬ ‫ﻜﻠﻭﺭﻴﺩ‬ ‫ﺒﺭﻴﺩﻨﻴﻭﻡ‬ ‫ﺴﻴﺘﻴل‬ ‫ﺍﻟﻤﻠﺨﺹ‬ ‫ﺍﻟﺘﺘﺭﺍﺴﺎﻴﻜﻠﻴﻥ‬ ‫ﻫﻴﺩﺭﻭﻜﻠﻭﺭﻴﺩ‬ ‫ﻤﻥ‬ ‫ﺍﻟﺼﻐﺭ‬ ‫ﻓﻲ‬ ‫ﻤﺘﻨﺎﻫﻴﺔ‬ ‫ﻜﻤﻴﺎﺕ‬ ‫ﻟﺘﻘﺩﻴﺭ‬ ‫ﻁﻴﻔﻴﻪ‬ ‫ﻁﺭﻴﻘﺔ‬ ‫ﺍﻗﺘﺭﺍﺡ‬ ‫ﺘﻡ‬. ‫ﺘﻌ‬ ‫ﺘﻤﺩ‬ ‫ﺍﻟﻤﺅﺯﻭﺕ‬ ‫ﺍﻟﻌﺎﻤل‬ ‫ﻤﻊ‬ ‫ﺍﻟﺘﺘﺭﺍﺴﺎﻜﻠﻴﻥ‬ ‫ﺍﻗﺘﺭﺍﻥ‬ ‫ﻋﻠﻰ‬ ‫ﺍﻟﻁﺭﻴﻘﺔ‬ 4-‫ﻜﻠﻭﺭﻴﺩ‬ ‫ﺒﺭﻴﺩﻨﻴﻭﻡ‬ ‫ﺴﻴﺘﻴل‬ ‫ﺒﻭﺠﻭﺩ‬ ‫ﺒﺎﻴﺭﻴﻥ‬ ‫ﺍﻤﻴﻨﻭﺍﻨﺘﻲ‬ ‫ﺍﻟﻘﺎﻋﺩﻱ‬ ‫ﺍﻟﻭﺴﻁ‬ ‫ﻓﻲ‬. ‫ﺍﻟﻤﺘﻜﻭﻨﺔ‬ ‫ﻟﻠﺼﺒﻐﺔ‬ ‫ﺍﻟﻤﻭﻻﺭﻱ‬ ‫ﺍﻻﻤﺘﺼﺎﺹ‬ ‫ﻤﻌﺎﻤل‬ ‫ﻗﻴﻤﺔ‬ ‫ﺒﻠﻐﺕ‬ 1.92 × 10 4 ‫ﻟﺘﺭ‬. ‫ﻤﻭل‬-1. ‫ﺴﻡ‬-1 ‫ﺍﻻﻋﻅﻡ‬ ‫ﺍﻟﻤﻭﺠﻲ‬ ‫ﺍﻟﻁﻭل‬ ‫ﻋﻨﺩ‬ 537 ‫ﻨﺎﻨﻭﻤﻴﺘﺭ‬. ‫ﺒ‬ ‫ﻗﺎﻨﻭﻥ‬ ‫ﺍﻟﻁﺭﻴﻘﻪ‬ ‫ﻭﺘﺘﺒﻊ‬ ‫ﻤﻥ‬ ‫ﺍﻟﺘﺭﺍﻜﻴﺯ‬ ‫ﻤﺩﻯ‬ ‫ﻓﻲ‬ ‫ﻴﺭ‬ 10 ‫ﺍﻟﻰ‬ 300 ‫ﻤﺎﻴﻜﺭﻭﻏﺭﺍﻡ‬ / 10 ‫ﻤل‬) ‫ﻤﻥ‬ ‫ﺃﻱ‬ 1-30 ‫ﺠﺯﺀ‬ / ‫ﻤﻠﻴﻭﻥ‬ .(‫ﺠﻴﺩﺓ‬ ‫ﺒﺎﺴﺘﻘﺭﺍﺭﻴﺔ‬ ‫ﺍﻟﻠﻭﻨﻲ‬ ‫ﺍﻟﺘﻔﺎﻋل‬ ‫ﻴﻤﺘﺎﺯ‬ ‫ﻭ‬ ‫ﺒ‬ ‫ﻨﺴﺒﻲ‬ ‫ﺨﻁﺄ‬ ‫ﻴﺘﺭﺍﻭﺡ‬ ‫ﺒﻴﻥ‬ 2.5-‫ﻭ‬ 0.21 % ‫ﻭ‬ ‫ﺒﻴﻥ‬ ‫ﻨﺴﺒﻲ‬ ‫ﻗﻴﺎﺴﻲ‬ ‫ﺍﻨﺤﺭﺍﻑ‬ 0.37± ‫ﻭ‬ % 0.73± ‫ﺍﻋﺘﻤﺎﺩﺍ‬ ‫ﻤﺴﺘﻭﻯ‬ ‫ﻋﻠﻰ‬ ‫ﺍﻟ‬ ‫ﺘﺭﻜﻴﺯ‬. ‫ﺘﻡ‬ ‫ﺘﻘﺩﻴﺭ‬ ‫ﻓﻲ‬ ‫ﺒﻨﺠﺎﺡ‬ ‫ﺍﻟﻁﺭﻴﻘﺔ‬ ‫ﺘﻁﺒﻴﻕ‬ ‫ﻫﻴﺩﺭﻭﻜ‬ ‫ﺍﻟﺘﺘﺭﺍﺴﺎﻴﻜﻠﻴﻥ‬ ‫ﻠﻭﺭﻴﺩ‬ ‫ﻓﻲ‬ ‫ﺍﻟﺼﻴﺩﻻﻨﻴﺔ‬ ‫ﺍﻟﻤﺴﺘﺤﻀﺭﺍﺕ‬ .