Ultrasound-assisted emulsification solidified floating organic drop microextraction for the determination of trace cadmium in water samples by flame atomic absorption spectrometry

Abstract

Uma técnica de microextração em fase líquida foi desenvolvida para a extração e determinação de quantidades traço de íons cádmio em amostras de água. A emulsificação-microextração assistida por ultrasom através da gota orgânica flutuante solidificada (USAE-SFODME) foi empregada para a extração e a espectrometria de absorção atômica com chama (FAAS) foi empregada para a determinação de Cd. Foram investigados e otimizados os fatores que influenciam na eficiência da técnica de microextração, tais como tipo e volume de solvente, tempo, temperatura, pH, quantidade do agente quelante e efeito da concentração de cloreto de sódio. Usando as condições otimizadas, um fator do enriquecimento de 81,0 foi obtido para um volume de 6,0 mL de amostra de água. A curva analítica de calibração mostrou-se linear no intervalo de 10-450 mg L -1 com um limite de detecção (LOD) igual a 0,66 mg L -1 de Cd. Os desvios padrão relativos (RSD) para dez replicatas de soluções contendo 20 e 300 mg L -1 de Cd foram 3,34% e 2,42%, respectivamente. O método proposto foi avaliado pela determinação de Cd em material de referência certificado de água ou através de experimentos de adição e recuperação.A liquid-phase microextraction technique was developed using ultrasound-assisted emulsification solidified floating organic drop microextraction (USAE-SFODME) combined with flame atomic absorption spectrometry (FAAS) for the extraction and determination of trace cadmium in water samples. Microextraction efficiency factors, such as extraction solvent type and extraction volume, time, temperature, pH, the amount of the chelating agent, and salt effect, were investigated and optimized. Under optimum conditions, an enrichment factor of 81.0 was obtained for 6.0 mL of water sample. The calibration graph was linear in the range of 10-450 mg L -1 with a detection limit of 0.66 mg L -1 . The relative standard deviations (RSD) for ten replicate measurements of 20 and 300 mg L -1 of Cd were 3.34% and 2.42%, respectively. The accuracy of the proposed method was assessed either by determination of Cd in a certified reference material of water or by addition-recovery experiments.

A Strategy Based on the Dispersive Liquid-Liquid Microextraction of Cadmium in Environmental Samples Prior to Its Determination by Flame Atomic Absorption Spectrometry

“…A comparison of the proposed method with other reported extrac-tion and preconcentration methods for Cd 2+ determination is given in Table VI (12,(32)(33)(34)(35)(36)(37). The DLLME method has several advantages andincludes short extraction time, negligible consumption of extraction solvents, and simplicity.…”

Supramolecular solvent based microextraction for the preconcentration of Pb2+ and Cd2+ prior to spectrophotometric detection

“…Hence, analyte loss was observed in the form of decreased recovery percentage. Complex degradability at such high temperature can be another important reason for this decrease in % recoveries [25]. Therefore, 35 ⁰C was selected as optimum temperature and 10 minutes as incubation time for further experimental work.…”

Ultrasound-assisted emulsification microextraction and preconcentration of trace amounts of silver ions as a cyclam complex

“…In USAEME, extraction time is defined as the time between the addition of extraction solvent and the end of the sonication stage (Zhang et al 2011). Enough sonication time will make the extraction solvent disperse more finely into the aqueous solution and results in an excellent cloudy solution and better extraction efficiency.…”