Hendricks Nokwanda, Olatunji Olatunde S, Gumbi Bhekumuzi P
School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4001, South Africa.
Heliyon. 2022 Nov 9;8(11):e11454. doi: 10.1016/j.heliyon.2022.e11454. eCollection 2022 Nov.
This paper presents a developed analytical technique for risk assessment of colloidal fullerene in surface waters by ultrasonic-assisted dispersive liquid-liquid extraction (UADLLE) and high-performance liquid chromatography ultraviolet-visible detector (HPLC-UV). Fullerene colloidal nanoparticles were synthesised and characterized by high-resolution transmission electron microscopy (HRTEM) and ultraviolet-visible spectroscopy (UV-Vis). Ultrasonication step, disperser solvent, and sodium chloride salt enhance the surface area of fullerene derivative aggregates for better contact and lowers the solubility of fullerene derivative to the aqueous solution, respectively promoting mass transfer of fullerene from aqueous into the organic phase. Several extraction parameters were optimized, and the optimal conditions were established: 5 mL toluene as extraction solvent (2 cycles); 200 mL water sample; 1% sodium chloride salt; 15 min ultrasonication, and 400 μL methanol as disperser solvent. The mean absolute recoveries established in drinking water, wastewater, and river water were 117%, 103%, and 93%, respectively. The proposed analytical technique was linear in the ranges between 0.25 μg L - 250 μg L with an r-squared of 0.9958. The limit of detection (LOD) determined from the signal-to-noise ratio of 3 was 0.11 μg L and the limit of quantification (LOQ) from a signal-to-noise ratio of 10 was 0.38 μg L. The precision ranges from 2% to 11% and accuracy percent error ranged from 7%-14% for spiked concentration levels of 0.25 μg L, 50 μg L and 250 μg L. The measured environmental concentration (MECs) for the fullerene in water samples ranged from not detected to 10.54 μg L and ecological assessment showed the concentration level of the fullerene can pose risk. Overall, according to the author's knowledge, this is the earlier work on the occurrence and risk assessment of fullerene colloidal nanoparticles (C61-PCBM) in potable and wastewater on the African continent.
本文介绍了一种通过超声辅助分散液液萃取（UADLLE）和高效液相色谱紫外可见检测器（HPLC-UV）对地表水中胶体富勒烯进行风险评估的先进分析技术。合成了富勒烯胶体纳米颗粒，并通过高分辨率透射电子显微镜（HRTEM）和紫外可见光谱（UV-Vis）对其进行了表征。超声步骤、分散剂溶剂和氯化钠盐分别增加了富勒烯衍生物聚集体的表面积以促进更好的接触，并降低了富勒烯衍生物在水溶液中的溶解度，从而促进富勒烯从水相转移到有机相。优化了几个萃取参数，并确定了最佳条件：5 mL甲苯作为萃取溶剂（2个循环）；200 mL水样；1%氯化钠盐；15分钟超声处理，以及400 μL甲醇作为分散剂溶剂。在饮用水、废水和河水中确定的平均绝对回收率分别为117%、103%和93%。所提出的分析技术在0.25 μg L至250 μg L范围内呈线性，决定系数为0.9958。根据信噪比为3确定的检测限（LOD）为0.11 μg L，根据信噪比为10确定的定量限（LOQ）为0.38 μg L。对于0.25 μg L、50 μg L和250 μg L的加标浓度水平，精密度范围为2%至11%，准确度百分比误差范围为7%至14%。水样中富勒烯的实测环境浓度（MECs）范围为未检测到至10.54 μg L，生态评估表明富勒烯的浓度水平可能带来风险。总体而言，据作者所知，这是非洲大陆上关于饮用水和废水中富勒烯胶体纳米颗粒（C61-PCBM）的存在及风险评估的早期工作。
