Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Using Deep Eutectic Solvents (DESs) for Neutral Red Dye Spectrophotometric Determination
Sana Ullah,
Hameed Ul Haq,
Muhammad Salman,
Faheem Jan,
Faisal Safi,
Muhammad Balal Arain,
Muhammad Shahzeb Khan,
Roberto Castro-Muñoz,
Grzegorz Boczkaj
Affiliations
Sana Ullah
Department of Chemistry, University of Malakand, Chakdara 18800, Pakistan
Hameed Ul Haq
Department of Sanitary Engineering, Faculty of Civil and Environmental Engineering, Gdansk University of Technology, G. Narutowicza St. 11/12, 80-233 Gdansk, Poland
Muhammad Salman
Department of Chemistry, University of Malakand, Chakdara 18800, Pakistan
Faheem Jan
School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
Faisal Safi
Department of Advanced Materials Center, Faculty of Electronics, Telecommunications and Informatics, Gdańsk University of Technology, G. Narutowicza St. 11/12, 80-233 Gdańsk, Poland
Muhammad Balal Arain
Department of Chemistry, University of Karachi, Karachi 75270, Pakistan
Muhammad Shahzeb Khan
Department of Chemistry and Technology of Functional Materials, Faculty of Chemistry, Gdansk University of Technology, G. Narutowicza St. 11/12, 80-233 Gdansk, Poland
Roberto Castro-Muñoz
Department of Sanitary Engineering, Faculty of Civil and Environmental Engineering, Gdansk University of Technology, G. Narutowicza St. 11/12, 80-233 Gdansk, Poland
Grzegorz Boczkaj
Department of Sanitary Engineering, Faculty of Civil and Environmental Engineering, Gdansk University of Technology, G. Narutowicza St. 11/12, 80-233 Gdansk, Poland
Deep eutectic solvents (DES), which have low toxicity and are low cost, biodegradable, and easily synthesized, were used for the extraction of neutral red (NR) dye before its spectrophotometric analysis. DES, containing choline chloride as a hydrogen bond acceptor and phenol as a hydrogen bond donor with a molar ratio of 1:2, was used for the extraction of NR dye from aqueous media. The possible interaction of different DESs with NR was studied using density functional theory (DFT) calculations. Experimentally, a UV-visible spectrophotometer was used for the quantitative analysis. The most important parameters affecting method performance, such as pH, extraction temperature, DES type, its volume, THF volume, sonication time, and centrifugation time, were optimized. The developed method provides exceptional sensitivity in terms of LOD and LOQ, which were 2.2 and 7.3 µg/L respectively. The relative standard deviation was 1.35–1.5% (n = 10), and the pre-concentration factor was 40. The method was found to be linear in the range of 2–300 µg/L (R2 = 0.9967). The method was successfully used for the determination of NR in wastewater samples. Finally, the DES-based method presents operational simplicity, high sensitivity, and rapid determination (<5 min) compared with other analytical procedures.
