caa a22 4500 463218752 CHVBK 20180405153205.0 cr unu---uuuuu 170326e20070601xx s 000 0 eng 10.1134/S1061934807060068 doi (NATIONALLICENCE)springer-10.1134/S1061934807060068 A new cloud-point preconcentration approach for the spectrophotometric determination of p-aminophenol in the presence of paracetamol with 2-(2-Hydroxyphenyl)-1H-benzimidazole as a coupling reagent [Elektronische Daten] [H. Filik, A. Tavman] A preconcentration and determination method for trace p-aminophenol (PAP) in paracetamol was developed. Cloud-point extraction (CPE) was employed for the preconcentration of p-aminophenol prior to spectrophotometric determination using Triton X-100 (TX-100) as an extractant. The determination is based on the reaction of p-aminophenol with 2-(2-hydroxyphenyl)-1H-benzimidazole (HPBI) at room temperature in the presence of an oxidant to produce indophenol blue dye. The dye formed is subsequently entrapped in micelles of the surfactant TX-100. The surfactant-rich phase shows maximum absorbance at 650 nm and the proposed method is linear in the 0.1 to 5.0 mg mL−1 concentration range. By preconcentrating 10 mL of the sample solution, a detection limit as low as 55 ng/mL was obtained after a single-step extraction and the experimental concentration factor achieved for this method was found to be 10. The stoichiometric composition of the dye is 1: 1 (PAP: HPBI). Some parameters such as HPBI, KIO4, Na2CO3, and TX-100 concentration, extraction temperature, incubation, and centrifugation time, and the sample volume were investigated in detail. The established procedure was successfully adopted for the determination of p-aminophenol in the presence of paracetamol in various pharmaceutical preparations. Pleiades Publishing, Ltd., 2007 cloud-point extraction nationallicence preconcentration nationallicence paracetamol nationallicence p-aminophenol nationallicence spectrophotometry nationallicence benzimidazole nationallicence Filik H. Faculty of Engineering, Department of Chemistry, Istanbul University, 34320, Avcilar, Istanbul, Turkey aut Tavman A. Faculty of Engineering, Department of Chemistry, Istanbul University, 34320, Avcilar, Istanbul, Turkey aut Journal of Analytical Chemistry Nauka/Interperiodica 62/6(2007-06-01), 530-535 1061-9348 62:6<530 2007 62 10809 https://doi.org/10.1134/S1061934807060068 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S1061934807060068 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Filik H. Faculty of Engineering, Department of Chemistry, Istanbul University, 34320, Avcilar, Istanbul, Turkey aut NATIONALLICENCE 700 1- Tavman A. Faculty of Engineering, Department of Chemistry, Istanbul University, 34320, Avcilar, Istanbul, Turkey aut NATIONALLICENCE 773 0- Journal of Analytical Chemistry Nauka/Interperiodica 62/6(2007-06-01), 530-535 1061-9348 62:6<530 2007 62 10809 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer