Ionic Liquid-Based Centrifuge-Less Cloud Point Extraction of a Copper(II)–4-Nitrocatechol Complex and Its Analytical Application
A novel centrifuge-less cloud point extraction (CL-CPE) method was developed for the spectrophotometric determination of copper(II) using 4-nitrocatechol (4NC) as the chelating agent. The extraction system utilizes a mixed micellar phase composed of the nonionic surfactant Triton X-114 and the ionic...
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2025-08-01
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| author | Denitsa Kiradzhiyska Nikolina Milcheva Miglena Ruzmanova Fatma Genç Petya Racheva Kiril Gavazov |
| author_facet | Denitsa Kiradzhiyska Nikolina Milcheva Miglena Ruzmanova Fatma Genç Petya Racheva Kiril Gavazov |
| author_sort | Denitsa Kiradzhiyska |
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| description | A novel centrifuge-less cloud point extraction (CL-CPE) method was developed for the spectrophotometric determination of copper(II) using 4-nitrocatechol (4NC) as the chelating agent. The extraction system utilizes a mixed micellar phase composed of the nonionic surfactant Triton X-114 and the ionic liquid (IL) Aliquat<sup>®</sup> 336 (A336). The extracted ternary ion-association complex, identified as (A336<sup>+</sup>)<sub>2</sub>[Cu(4NC)<sub>2</sub>], exhibits a maximum absorbance at 451 nm, with a molar absorption coefficient of 8.9 × 10<sup>4</sup> M<sup>−1</sup> cm<sup>−1</sup> and a Sandell’s sensitivity of 0.71 ng cm<sup>−2</sup>. The method demonstrates a linear response in the copper(II) concentration range of 32–763 ng mL<sup>−1</sup> and a limit of detection of 9.7 ng mL<sup>−1</sup>. The logarithmic extraction constant (log <i>K</i><sub>ex</sub>) was determined to be 7.9, indicating efficient extraction. Method performance, evaluated by the Blue Applicability Grade Index (BAGI) and the Click Analytical Chemistry Index (CACI), confirmed its feasibility, practicality, simplicity, convenience, cost-effectiveness, environmental friendliness, and analytical competitiveness. The proposed IL-CL-CPE method was successfully applied to the analysis of a dietary supplement, a solution for infusion, and synthetic mixtures simulating various copper alloys. |
| format | Article |
| id | doaj-art-8e70618feff74ca7bbf45abff814c081 |
| institution | DOAJ |
| issn | 1420-3049 |
| language | English |
| publishDate | 2025-08-01 |
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| series | Molecules |
| spelling | doaj-art-8e70618feff74ca7bbf45abff814c0812025-08-20T03:04:43ZengMDPI AGMolecules1420-30492025-08-013015328710.3390/molecules30153287Ionic Liquid-Based Centrifuge-Less Cloud Point Extraction of a Copper(II)–4-Nitrocatechol Complex and Its Analytical ApplicationDenitsa Kiradzhiyska0Nikolina Milcheva1Miglena Ruzmanova2Fatma Genç3Petya Racheva4Kiril Gavazov5Research Institute at the Medical University of Plovdiv, 15A, Vassil Aprilov Blvd., 4002 Plovdiv, BulgariaResearch Institute at the Medical University of Plovdiv, 15A, Vassil Aprilov Blvd., 4002 Plovdiv, BulgariaDepartment of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, BulgariaFaculty of Pharmacy, Yeni Yüzyıl Üniversitesi, 26 Yılanlı Ayazma Caddesi, Istanbul 34010, TurkeyDepartment of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, BulgariaDepartment of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, BulgariaA novel centrifuge-less cloud point extraction (CL-CPE) method was developed for the spectrophotometric determination of copper(II) using 4-nitrocatechol (4NC) as the chelating agent. The extraction system utilizes a mixed micellar phase composed of the nonionic surfactant Triton X-114 and the ionic liquid (IL) Aliquat<sup>®</sup> 336 (A336). The extracted ternary ion-association complex, identified as (A336<sup>+</sup>)<sub>2</sub>[Cu(4NC)<sub>2</sub>], exhibits a maximum absorbance at 451 nm, with a molar absorption coefficient of 8.9 × 10<sup>4</sup> M<sup>−1</sup> cm<sup>−1</sup> and a Sandell’s sensitivity of 0.71 ng cm<sup>−2</sup>. The method demonstrates a linear response in the copper(II) concentration range of 32–763 ng mL<sup>−1</sup> and a limit of detection of 9.7 ng mL<sup>−1</sup>. The logarithmic extraction constant (log <i>K</i><sub>ex</sub>) was determined to be 7.9, indicating efficient extraction. Method performance, evaluated by the Blue Applicability Grade Index (BAGI) and the Click Analytical Chemistry Index (CACI), confirmed its feasibility, practicality, simplicity, convenience, cost-effectiveness, environmental friendliness, and analytical competitiveness. The proposed IL-CL-CPE method was successfully applied to the analysis of a dietary supplement, a solution for infusion, and synthetic mixtures simulating various copper alloys.https://www.mdpi.com/1420-3049/30/15/3287copper(II)mixed micelle-mediated systemAliquat 3361,2-dihydroxy-4-nitrobenzenecentrifuge-less cloud point extractionspectrophotometric determination |
| spellingShingle | Denitsa Kiradzhiyska Nikolina Milcheva Miglena Ruzmanova Fatma Genç Petya Racheva Kiril Gavazov Ionic Liquid-Based Centrifuge-Less Cloud Point Extraction of a Copper(II)–4-Nitrocatechol Complex and Its Analytical Application Molecules copper(II) mixed micelle-mediated system Aliquat 336 1,2-dihydroxy-4-nitrobenzene centrifuge-less cloud point extraction spectrophotometric determination |
| title | Ionic Liquid-Based Centrifuge-Less Cloud Point Extraction of a Copper(II)–4-Nitrocatechol Complex and Its Analytical Application |
| title_full | Ionic Liquid-Based Centrifuge-Less Cloud Point Extraction of a Copper(II)–4-Nitrocatechol Complex and Its Analytical Application |
| title_fullStr | Ionic Liquid-Based Centrifuge-Less Cloud Point Extraction of a Copper(II)–4-Nitrocatechol Complex and Its Analytical Application |
| title_full_unstemmed | Ionic Liquid-Based Centrifuge-Less Cloud Point Extraction of a Copper(II)–4-Nitrocatechol Complex and Its Analytical Application |
| title_short | Ionic Liquid-Based Centrifuge-Less Cloud Point Extraction of a Copper(II)–4-Nitrocatechol Complex and Its Analytical Application |
| title_sort | ionic liquid based centrifuge less cloud point extraction of a copper ii 4 nitrocatechol complex and its analytical application |
| topic | copper(II) mixed micelle-mediated system Aliquat 336 1,2-dihydroxy-4-nitrobenzene centrifuge-less cloud point extraction spectrophotometric determination |
| url | https://www.mdpi.com/1420-3049/30/15/3287 |
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