Fe(III) hepthyldithocarbamate as a new collector for flotation separation and preconcentration of Cr, Cu, and Pb from fresh waters before their determination by ETAAS

Abstract

eletrotérmica (ETAAS). A possibilidade da aplicação de heptilditiocarbamato de ferro(III), Fe(HpDTC) 3 , como coletor foi estudada. Os parâmetros experimentais que influenciam a eficiência da flotação do coletor foram otimizados. Constatou-se que Cr(III), Cr(VI), Cu(II) e Pb(II) podem ser separados simultaneamente pela adição de 20 mg de Fe(III) e 6 mL de HpDTC -0,1 mol L -1 a 1 L de uma amostra teste, em pH 6,5. O fator de preconcentração do método é 40. A aplicabilidade do novo procedimento proposto foi verificada pelo método de adições padrão e por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) como um método comparativo independente. O limite de detecção para Cu pelo método de flotação/ ETAAS é 0,015 µg L -1 , 0,011 µg L -1 para Cr e 0,025 µg L -1 para Pb. Determinou-se que para concentrações baixas (de 0,025 a 0,2 µg L -1 ), o RSD para Cu é 1,5%; para Cr, 4,2% e para Pb é 7,8%; enquanto que para níveis de concentração mais altos (de 0,2 a 4,5 µg L -1 ), RSD para Cu é 1,7%, para Cr 2,8% e para Pb é 3,7%.A method for determination of Cr, Cu and Pb in fresh waters, after flotation separation and preconcentration step, by using electrothermal atomic absorption spectrometry (ETAAS) is presented. The possibility of applying iron(III) hepthyldithiocarbamate, Fe(HpDTC) 3 , as a collector is studied. The experimental parameters affecting the flotation efficiency by a new collector were optimized. It is ascertained that Cr(III), Cr(VI), Cu(II) and Pb(II) can be separated simultaneously from matrix by addition of 20 mg Fe(III) and 6 mL 0.1 mol L -1 HpDTC -to a test sample of 1 L at pH 6.5. The preconcentration factor of the method is 40. The applicability of the new proposed procedure was verified by the method of standard additions and by inductively coupled plasma optical emission spectrometry (ICP OES), as an independent comparative method. The limit of detection for Cu by flotation/ETAAS method is 0.015 µg L -1 , for Cr is 0.011 µg L -1 , and for Pb 0.025 µg L -1 . It was found that for low concentrations (from 0.025-0.2 µg L -1 ) RSD for Cu is 1.5%, for Cr 4.2% and for Pb is 7.8%, while for the higher concentration level (from 0.2-4.5 µg L -1 ) RSD for Cu is 1.7%, for Cr 2.8% and for Pb is 3.7%.

Bio-fortification potential of global wild annual lentil core collection

“…Among minerals, deficiencies specifically of iron exists within nearly 3.7 billion people worldwide comprising about 60% of the whole population [ 2 ], whereas zinc affecting about one-third of the world population [ 3 ], are the most common. Adequate amounts of copper, manganese, molybdenum, cobalt, nickel, sodium and potassium are also required in body as these act as components of various enzymes or vitamins [ 4 ] or involved in other metabolic activities [ 5 ]. Atleast one physiological function is known for each of the nine trace elements namely iron, zinc, copper, manganese, molybdenum, chromium, fluoride, iodine and selenium in human metabolism and these are ranked as essential micronutrients and should be consumed regularly in food or as supplements [ 6 , 7 ].…”

Electrothermal atomic absorption spectrometric determination of cadmium and lead in traces in aquatic systems following flotation by two chromium(III) collectors

“…It should be mentioned also that lower detection limits for cadmium and lead is one of the advantage of the new proposed collectors compared with the previously used two collector systems of Fe 2 O 3 · xH 2 O and iron tetramethylenedithiocarbamate, Fe(TMDTC) 3 , [39] iron hexamethylenedithiocarbamate, Fe(HMDTC) [20,40] 3 and iron heptyldithiocarbamate, Fe(HpDTC) 3 . [33] …”

“…Its role as a collector is not decisive for total quantitative removing of analytes from water media at lower pHs, which is sometimes very important criterion to separate heavy metals from alkaline earth metals present in some water matrices. [27][28][29][30]32,33] Therefore coprecipitation with Cr 2 O 3 · xH 2 O had to be modified and ameliorated by addition of PMA-PMDTC to form Cr(PMDTC) 3 as an additional collector with far more ability to collect metal species quantitatively at lower pHs.…”