Determination of trace metals in waters and compost by on-line precipitation coupled to flame atomic absorption spectrophotometry or ion chromatography

Departamento de Quı́mica Analı́tica. Facultad de Ciencias Quı́micas. Universidad Complutense de Madrid. 28040 Madrid, Spain
Talanta (Impact Factor: 3.55). 04/1999; 48(4):959-966. DOI: 10.1016/S0039-9140(98)00303-8


A general rapid on-line preconcentration method for the determination of trace metals coupled to flame atomic absorption spectrophotometry (FAAS) or ion chromatography (IC) with spectrophotometric detection is described. The method is based on the on-line precipitation of metal hydroxides with sodium hydroxide and their dissolution in a small volume of nitric acid solution. All the chemical and physical variables that affect the efficiency of metal precipitation and elution in the flow injection system have been studied. The detection limits obtained by FAAS are 0.1, 0.3, 0.5 and 0.5 μg l−1 for Zn, Cu, Ni and Pb, respectively. When the on-line precipitation is coupled to IC with post-column derivatization with the spectrophotometric reagent 4-(2-pyridylazo) resorcinol (PAR), the detection limits are 3, 1, 5, 3, and 3 μg l−1 for Cu, Zn, Ni, Co and Mn, respectively. The proposed general method was successfully applied to determine independently the above mentioned metals in compost and tap and river water samples.

1 Follower
9 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this work, the speciation of elements in compost was studied with emphasis on their binding to humic substances. In order to assess the distribution of As, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, U, Th and Zn among molecular weight fractions of humic substances, the compost extract (extracted by 0.1 mol l(-1) sodium pyrophosphate) was analyzed by size exclusion chromatography coupled on-line with UV-Vis spectrophotometric and ICP-MS detection. Similar chromatograms were obtained for standard humic acid (Fluka) and for compost extract (254 nm, 400 nm) and three size fractions were operationally defined that corresponded to the apparent molecular weight ranges > 15 kDa, 1-15 kDa and < 1 kDa. The percentage of total element content in compost that was leached to the extract ranged from 30% up to 100% for different elements. The elution profiles of Co, Cr, Cu, Ni and Pb (ICP-MS) followed that of humic substances, while for other elements the bulk elution peak matched the retention time observed for the element in the absence of compost extract. Spiking experiments were carried out to confirm elements' binding and to estimate the affinity of individual elements for humic substances derived from compost. The results obtained indicated the following order of decreasing affinity: Cu > Ni > Co > Pb > Cd > (Cr, U, Th) > (As, Mn, Mo, Zn). After standard addition, further binding of Cu, Ni and Co with the two molecular weight fractions of humic substances was observed, indicating that humic substances derived from compost were not saturated with these elements.
    Journal of Environmental Monitoring 12/2002; 4(6):1010-6. DOI:10.1039/B206985G · 2.18 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A membrane filtration procedure for the preconcentration of nickel(II), cadmium(II), copper(II), cobalt(II) and lead(II) ions has been established. The analytes were adsorbed on cellulose nitrate membrane filter as their ammonium pyrrolydine dithiocarbamate (APDC) complexes. Then membrane filter was dissolved by using nitric acid. The levels of the analytes in the final solutions were determined by flame atomic absorption spectrometry (FAAS). The analytical parameters including pH, amounts of APDC, sample volume, matrix effects, etc. have been optimized. The present method has been successfully applied for the FAAS determinations of analyte ions in a stream sediment reference material (GBW 07309), table salts and natural water samples with good results, e.g. recoveries greater than 95%, relative standard deviations generally lower than 9%. The analyte ion levels of the microwave digested urine and black tea samples were also analyzed by using proposed preconcentration procedure.
    Analytica Chimica Acta 10/2003; 493(2-493):205-212. DOI:10.1016/S0003-2670(03)00867-5 · 4.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A review is presented detailing the development of ion chromatography (IC) as a selective analytical tool for the determination of toxic metals and their organic species in many environmental sample matrices. A brief outline of ion chromatographic principles, together with an overview of the stationary phases used to separate metals, namely ion exchangers, modified ion pair sorbents and chelating ion exchangers, and the methods for detecting metal ions including hyphenation with spectroscopy and sample preparation schemes are also given, prior to a critical examination of developed methods for various metals including arsenic, chromium, cadmium, lead, mercury, beryllium, aluminium and uranium since 1990.
    Environment International 06/2004; 30(3):403-31. DOI:10.1016/j.envint.2003.09.009 · 5.56 Impact Factor
Show more