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The simultaneous determination of copper and zinc in human plasma and urine by inductively coupled plasma mass spectrometry (ICP MS) is discussed. The performances of a cross-flow nebulizer and a direct-injection nebulizer (DIN) were compared. Flow-injection-DIN-ICP MS analysis of clinical samples using 1–2 μl samples was optimized. Isobaric interferences were discussed and were demonstrated to be...
Infant formula and powdered milk samples were suspended in a medium containing 20% ethanol, 0.65% nitric acid, 6% hydrogen peroxide and 0.1% ammonium dihydrogenphosphate and directly introduced in the electrothermal atomizer. Liquid milk samples were diluted with this suspension solution. The build-up of carbonaceous residues inside the atomizer was avoided by using a combination of hydrogen peroxide...
A method for the simultaneous spectrophotometric determination of the divalent ions of iron, cobalt, nickel and copper based on the formation of their complexes with 1,5-bis(di-2-pyridylmethylene) thiocarbonohydrazide (DPTH) is proposed. The resolution of quaternary mixtures of these metallic ions was accomplished by several chemometric approaches. A comparative study of the results obtained for simultaneous...
Three new 8-aminoquinoline-5-azo derivatives: 5-(3-fluo-4-chlorophenylazo)-8-aminoquinoline (FCPAQ), 5-(3-fluo-4-chlorophenylazo)-8-benzenesulfonamidoquinoline (FCPBSQ), 4,4'-bis(8-aminoquinoline-5-azo)-biphenyl (BAQABP) have been synthesized, and were found to be good fluorescence reagents for the determination of copper(II). In slightly acidic or basic medium, copper(II) reacts with FCPAQ, FCPBSQ...
The synthesis of the new long-chain saturated fatty hydrocarbon substituting group compound, N-undecyl-N'-(sodium p-aminobenzenesulfonate)-thiourea (UPT) is described. According to the studies on its analytical performance, it is found that this reagent can be used to identify Cu 2+ (PD 6.3) and determine microamounts of copper (ε 300.4nm =2...
A colorimetric flow injection-system for the determination of Cu(II) in waters based on complexation reaction with 4-(2-pyridylazo)-resorcinol, usually termed PAR, is described. Performing measurements in 0.25 mol l -1 HNO 3 medium allowed improved selectivity of the analytical method. The lack of sensitivity deriving from the low complex absorption under acidic conditions was...
A procedure for lead, cadmium and copper determination in coal samples based on slurry sampling using an atomic absorption spectrometer equipped with a transversely heated graphite tube atomizer is proposed. The slurries were prepared by weighing the samples directly into autosampler cups (5-30 mg) and adding a 1.5 ml aliquot of a diluent mixture of 5% v/v HNO 3 , 0.05% Triton X-100 and 10%...
Methods for the direct determination of copper and cadmium in seawater were described using a graphite furnace atomic absorption spectrometer (GFAAS) equipped with a transversely heated graphite atomizer (THGA) and a longitudinal Zeeman effect background corrector. Ammonium nitrate was used as the chemical modifier to determine copper. The mixture of di-ammonium hydrogen phosphate and ammonium nitrate...
A stable chelating resin matrix was synthesized by covalently linking o-aminophenol (o-AP) with the benzene ring of the polystyrene-divinylbenzene resin, Amberlite XAD-2, through a -N N- group. Elemental analyses, thermogravimetric analysis (TGA) and infrared spectra have characterized the resulting chelating resin. It has been used to preconcentrate Cu 2+ , Cd 2+ , Co ...
A simple and sensitive spectrophotometric method for determination of copper(II) is based on the formation of a blue coloured complex of Cu(II) with 9-phenyl-2,3,7-trihydroxy-6-fluorone (PF) in the presence of cetylpyridinium chloride (CP) and Triton X-100, has been developed. Optimum concentrations of PF, CP, Triton X-100 and pH ensuring maximum absorbance were defined. The complex Cu(II)-PF-CP-Triton...
A new preconcentration method with yeast is presented. The method was evaluated for the determination of trace copper in river water by graphite furnace atomic absorption spectrometry (GFAAS). A suitable cultivation bed for preconcentration of copper was 3.5 mg ml -1 2-ammonium hydrogen phosphate. The optimal cultivation time and temperature were 2 h and 40 o C. Under optimal...
A sensitive and selective kinetic method is proposed for the determination of nanogram amounts of copper. The method is based on the catalytic effect of copper on the reduction of Ponceau S by sodium sulfide in an alkaline media. The rate of the reaction is monitored spectrophotometrically at 560 nm. The method allows determination of copper concentrations in the range 2–400 ng ml −1 with...
A new flow injection on-line adsorption preconcentration system adapted to flame atomic absorption spectrometry (FAAS) for copper determination at the μg l -1 level was developed. Polytetrafluoroethylene (PTFE) turnings packed in a mini-column were used as sorbent material. The copper ammonium pyrrolidine dithiocarbamate (APDC) complex was sorbed on the PTFE turnings, from which it could...
A spectrofluorimetric method has been developed for the determination of trace Cu(II) in real samples with 4,5-dihydroxy-l,3-benzenedisulfonic acid (Tiron) as a fluorimetric reporter. Tiron is very soluble in water and is a good fluorimetric reagent. However, as Tiron was complexed with Cu(II), the fluorescence intensity decreased proportionally to the concentration of Cu(II) by a static quenching...
An electrochemical stripping procedure for ultra-trace measurements of adenine is described based on the adsorption of the adenine-copper complex on a static mercury drop electrode. Cyclic voltammetry was used to characterize the interfacial and redox behavior. Optimum experimental conditions were found when using a 0.005 M NaOH solution containing 0.4 ppm of copper, an accumulation potential of -0...
A flow system exploiting multicommutation and multidetection is proposed for sequential determinations in pharmaceutical preparations. The feasibilities were demonstrated by the determination of zinc, iron, copper, calcium and magnesium without changing the flow set-up. The gravitational flow of the solutions was exploited for addition of different chromogenic reagents and sample aliquots, thus avoiding...
The utility of carbon paste electrode modified with DTPT (3,4-dihydro-4,4,6-trimethyl-2(1H)-pyrimidine thione) for the potentiometric determination of Cu(II) in aqueous medium is demonstrated. The electrode exhibits linear response to Cu(II) over a wide concentration range (9.77x10 -7 -7.6x10 -2 ) with Nernstian slope of 30+/-2 mV per decade. It has a response time of about...
A tungsten-rhodium treatment on the integrated platform of a transversely heated graphite atomiser was used as a permanent chemical modifier for the determination of copper in biological materials by using digested samples as well as slurry sampling in electrothermal atomic absorption spectrometry. The W-Rh permanent modifier was as efficient as Pd+Mg(NO 3 ) 2 conventional modifier...
Screen-printed carbon electrodes (SPCEs), without chemical modification, have been investigated as disposable sensors for the measurement of trace levels of Cu 2+ . Cyclic voltammetry was employed to elucidate the electrochemical behaviour of Cu 2+ at these electrodes in a variety of supporting electrolytes. For all of the electrolytes studied the anodic peaks, obtained on...
Procedures are described for measurement of dissolved copper with long pathlength Teflon AF-2400 liquid core waveguides. Using a 4.4 m waveguide, absorbance versus concentration is linear for copper concentrations between 1 and 160 nM. The molar absorbance of copper complexed with bathocuproine disulfonate is nearly identical for pathlengths between 1 cm and 4.4 m. Our 4.4 m waveguide system provided...
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