Determination of trace amounts of copper in river and sea water samples by flame atomic absorption spectrometry (FAAS) after cloud-point preconcentration

Abstract

Este trabalho propõe um novo método de pré-concentração baseado em ponto nuvem para a determinação de cobre. O reagente 1,5-difenil-benzoína (Cupron) foi usado como complexante e Triton X-114 foi adicionado como surfactante. Após a separação das fases e diluição da fase rica em surfactante com metanol em meio acidificado foi feita a determinação do cobre por espectrometria de absorção atômica com chama (FAAS). O fator de enriquecimento do cobre, após a otimização das condições de complexação e otimização, foi igual a 88. O procedimento proposto possibilitou a determinação de cobre com limite de detecção igual a 0,04 μg L -1 . O procedimento foi aplicado com sucesso na determinação de cobre em amostras de água de rio e de mar. O desvio padrão relativo foi de 1,9 % para o Cu. Também foram investigados efeitos de interferência de alguns ânions e cátions.A new preconcentration method was proposed using the cloud point approach for copper determination. The reagent 1,5-diphenyl-benzoin (Cupron) was used as a complexing agent and Triton X-114 was added as a surfactant. After phase separation, dilution of the surfactantrich phase was carried out using acidified methanol and the copper content was subsequently measured by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions, the enrichment factor for Cu was found to be 88. The proposed procedure allowed determination of the copper content with the detection limit of 0.04 μg L -1 . The method was successfully applied to copper determination in river and sea water samples. The relative standard deviation for the method was found to be 1.9 % for Cu. The interference effects of some anions and cations were also investigated.

Determination of manganese‐ and manganese‐containing fungicides with lucigenin–Tween‐20‐enhanced chemiluminescence detection

“…In surface and ground water Co(II) is <1.0 µg L –1 in pristine areas and 1–10 µg L –1 in populated area and in seawater values are typically of the order of 0.02 nM and range from <0.01–0.1 nM , and can effectively be masked by the addition of dimethylglyoxime (20 μM) to the CL reagent . Goudarzi reported that Cu(II) concentrations in seawater and river water were 4.5 ± 0.1 and 5.8 ± 0.2 µg L –1 respectively. The US EPA has established 50 µg L –1 as the practical quantification limit for copper .…”

Highly sensitive colorimetric sensing of copper(ii) ions based on “CLICK-17” DNAzyme-catalyzed azide modified gold nanoparticles and alkyne capped dsDNA cycloaddition

“…As such, it is important to develop efficient, sensitive and selective methods for determination of trace amounts of copper. Some analytical techniques have been reported for copper determination including atomic absorption spectrometry (AAS), 9,13,14 inductively coupled plasma-atomic emission spectrometry (ICP-AES), 9 inductively coupled plasma-mass spectrometry (ICP-MS), 15 and electrochemical methods. 16 Although these methods have high selectivity and sensitivity, some drawbacks still exist.…”

Cloud point extraction for the determination of trace copper(II) in environmental samples using a new synthesized reagent and flame atomic absorption spectrometry

“…Several reports have been published on the preconcentration of copper by the CPE method. In all mentioned studies, copper has been preconcentrated by the CPE method after the formation of sparingly water-soluble complexes with a suitable chelating agent such as 8-hydroxyquinoline (Oxine), diethyldithiocarbamate (DDTC), 1-(2-pyridylazo)-2-naph thol (PAN), 1-(2-thiazolylazo)-2-naph t hol (TAN) and 4-(2-pyridylazo)resorci nol (PAR), 4-(2'-thiazolylazo)-resorcinol (TAR), 2 -(2-thiazolylazo)-p-cresol (TAC), 2 -(2-thiazo ly lazo)-4-methoxyphenol (TAMP) and others [7][8][9][10][11][12][13]. The CP of non-ionic surfactants can be conveniently decreased or increased by the presence of different additives (i.e., organic and inorganic additives), thus providing a way to use non-ionic surfactants under various conditions [14].…”