Solid-phase chelate extractive preconcentration of heavy metal ions prior to their ultratrace determination by microsample injection system coupled flame atomic absorption spectrometry.

Chromosorb-105 resin/1-(2-pyridylazo)-2-naphthol (PAN) system was developed for solid phase chelate extractive preconcentration of heavy metal ions. The metal ions on Chromosorb-105 resin column were eluted with 3.0 mL of 2.0 mol L-1 HNO3 and determined by microsample injection system coupled flame atomic spectrometry (MIS-FAAS) using 75.0 µL of sample solution for single element determination. The influence of pH, resin amount, reagent amount, flow rate and volume of eluent and sample solution was optimized. The quantitative recoveries (≥95%) of Fe(III), Zn(II), Cu(II) and Pb(II) ions were achieved at pH 9; resin amount, 700 mg; reagent amount, 6.0 µmol; flow rate of eluent and sample solution, 1.0 mL min-1 and 5.0 mL min-1, respectively. The limit of detection and limit of quantification of understudied analytes were found to be 0.17-1.74 µg L-1 and 0.40-2.98 µg L-1, respectively with preconcentration factor of 150-300. The proposed method was validated by analysis of waste water (BCR-715) as a certified reference material. The method was applied successfully for ultratrace determination of studied metal ions in tap water and hot spring water samples.

Determination of cobalt, nickel and iron at trace level in natural water samples by in-column chelation-reversed phase high-performance liquid chromatography.

This paper reports the utilization of 4-(2-pyridylazo) resorcinol (PAR) as a chelating reagent for in-column derivatization and the determination of trace Co, Fe, and Ni ions by reversed-phase high-performance liquid chromatography with photodiode array detector. A good separation of Co, Fe, and Ni chelates were achieved by using an Inertsil ODS-3 column and a mobile phase, consisted of methanol-THF-water mixture (50:5:45) containing ammonium acetate buffer (pH 5.0) and PAR. After full optimization, good repeatability of retention times (relative standard deviation (RSD) < 0.05%) and peak areas (RSD < 1.7%) was achieved as well as a good linearity (r (2) > 0.9991). The detection limits (S/N = 3), expressed as micrograms per liter, were 0.50 (Co), 9.07 (Fe), and 2.00 (Ni). The applicability and the accuracy of the developed method were estimated by the analysis of spiked water samples and certified reference material BCR 715 wastewater-SRM.

Solid-phase extraction of some heavy metal ions on a double-walled carbon nanotube disk and determination by flame atomic absorption spectrometry.

A new preconcentration method was developed for the determination of trace amounts of Cu(II), Fe(III), Pb(II), Ni(II), and Cd(II) on a double-walled carbon nanotube disk. 4-(2-Thiazolylazo) resorcinol was used as a complexing reagent. The effects of parameters, including pH of the solutions, amounts of complexing reagent, eluent type, sample volume, flow rates of solutions, and matrix ions were examined for quantitative recoveries of the studied analyte ions. The retained metal ions were eluted by 2 M HNO3. The LOD values for the analytes were in the range of 0.7-4.4 microg/mL. Natural water samples and standard reference materials were analyzed by the presented method.

Determination of some organophosphorus and azole group pesticides in water samples by dispersive liquid-liquid microextraction coupled with GC/MS.

A dispersive liquid-liquid microextraction (DLLME) procedure coupled with GC/MS detection is described for preconcentration and determination of some organophosphorus and azole group pesticides from water samples. Experimental conditions affecting the DLLME procedure were optimized by means of an experimental design. A mixture of 60 microL chlorobenzene (extraction solvent) and 750 microL acetonitrile (disperser solvent), 3.5 min extraction time, and 7.5 mL aqueous sample volume were chosen for the best recovery by DLLME. The linear range was 1.6-32 microg/L. The LOD ranged from 48.8 to 68.7 ng/L. The RSD values for organophosphorus and azole group pesticides at spiking levels of 3, 6, and 9 microg/L in water samples were in the range of 1.1-12.8%. The applicability and accuracy of the developed method were determined by analysis of spiked water samples, and the recoveries of the analyzed pesticides from artesian, stream, and tap waters at spiking levels of 3, 6, and 9 microg/L were 89.3-105.6, 89.5-103.0, and 92.0-111.3%, respectively.

Determination of lead in wine and rum samples by flow injection-hydride generation-atomic absorption spectrometry.

A method for direct determination of lead in wine and rum samples was developed, using a flow injection hydride generation system coupled to an atomic absorption spectrometer with flame-quartz atomizer (FI-HG-AAS). Lead hyride (PbH(4)) was generated using potassium ferricyanide (K(3)Fe(CN)(6)), as oxidant and sodium tetrahydroborate (NaBH(4)) as reductant. Samples were acidified to 0.40% (v/v) HCl for wine and to 0.30% (v/v) HCl for rum, which were then mixed on-line with 3% (m/v) K(3)Fe(CN)(6) solution in 0.03% (v/v) HCl prior to reaction with 0.2% (m/v) alkaline NaBH(4) solution. Lead contents of a rum and two different red wine samples were determined by FI-HG-AAS agreed with those obtained by ICP-MS. The analytical figures of merit of method developed were determined. The calibration curve was linear up to 8.0 microg L(-1) Pb with a regression coefficient of 0.998. The relative error was lower than 4.58%. The relative standard deviation (n=7) was better than 12%. A detection limit of 0.16 microg L(-1) was achieved for a sample volume of 170 microL.

Simultaneous preconcentration of Co(II), Ni(II), Cu(II), and Cd(II) from environmental samples on Amberlite XAD-2000 column and determination by FAAS.

A new method for the preconcentration of some trace metals (Co, Ni, Cu, and Cd) as complexed with ammonium pyrrolidynedithiocarbamate (APDC) was developed using a mini-column filled with Amberlite XAD-2000 resin. Metal contents were determined by flame atomic absorption spectrometry (FAAS) after the metal complexes accumulated on the resin were eluted with 1M HNO(3) in acetone. The effects of the analytical parameters such as sample pH, quantity of complexing agent, eluent type, resin quantity, sample volume, sample flow rate, and matrix ions were investigated on the recovery of the metals from aqueous solutions. The relative standard deviation (R.S.D.) of the method was <6%. The validation of the method was confirmed using two certified reference materials (CRM TMDW-500 Drinking Water and CRM SA-C Sandy Soil C). The method was successfully applied to some stream waters and mushroom samples from Eastern Black Sea Region (Trabzon city) of Turkey.

Extractable trace metals content of dust from vehicle air filters as determined by sequential extraction and flame atomic absorption spectrometry.

A modified four-step sequential extraction procedure developed within the Standards, Measurement, and Testing Program (formally the Community Bureau of Reference) of the European Commission was applied to determine the distribution of Cd, Cu, Fe, and Mn in air filter dust samples collected from vehicles. The four fractions were acid-soluble, reducible, oxidizable, and residual. These fractions have the advantage of providing better insight into the mechanism of association of metals in the dust. The determination of trace metals in dust samples was performed by flame atomic absorption spectrometry. The results obtained after applying the sequential extraction scheme indicated that Cu was the most abundant metal in the organic and residual fractions of the dust matrix. Fe was found mainly in the residual fraction, and the major amounts of Mn and Cd were present in the acid-soluble and bound-to-carbonate fraction. The mean values of Cd, Cu, Fe, and Mn were found to be 15.58, 33.54, 1625, and 180 microg/g, respectively. The results obtained are in agreement with data reported in the literature.

Use of an aminated Amberlite XAD-4 column coupled to flow injection cold vapour generation atomic absorption spectrometry for mercury speciation in water and fish tissue samples.

An aminated Amberlite XAD-resin as a solid phase extractant was tested for speciation of inorganic mercury, Hg(II) and methylmercury, MeHg(I) in water and fish tissue samples. It was found that Hg(II) and MeHg(I) ions could be simultaneously retained by a column filled with AAXAD-4 resin at pH 4 and the sequential quantitative elutions of Hg(II) and MeHg(I) were achieved using 10 mL of 0.1%(m/v) thiourea in 3%(v/v) HCl and 10 mL of 6 mol L-1 HCl, respectively. Hg(II) in the eluent was directly determined and MeHg(I) in the second eluent is quantified using FI-CVG-AAS after its oxidative digestion with KMnO4. The limits of detection for Hg(II) and MeHg(I) ions were found to be 0.148 and 0.157 µg L-1, respectively. The method was validated by analysing a certified reference material. The relative errors for Hg(II), MeHg(I) and T-Hg were in range of -1.8% and -3.2%.

Solid phase extraction method for the determination of iron, lead and chromium by atomic absorption spectrometry using Amberite XAD-2000 column in various water samples.

This work describes a procedure for the separation-preconcentration of Fe(III), Pb(II) and Cr(III) from some water samples using a column-filled Amberlite XAD-2000 resin. The analyte ions retained on the column were eluted with 0.5 mol L(-1) HNO(3). The analytes in the effluent were determined by atomic absorption spectrometry. Several parameters governing the efficiency of the method were evaluated including pH, resin amount, sample volume, flow rates, eluent type and divers ion effects. The recoveries under the optimum working conditions were found to be as 100+/-1% Fe, 96+/-1% Pb and 93+/-2% Cr. The relative standard deviations and errors were less than 2% and 5%, respectively. The detection limit based on three standard deviations of the blank was found to be 0.32, 0.51 and 0.81 microg L(-1), for Fe, Pb and Cr, respectively. The procedure was applied to the determination of Fe, Cr and Pb in hot spring water and drinking water samples.

Chromium speciation by solid phase extraction on Dowex M 4195 chelating resin and determination by atomic absorption spectrometry.

A solid phase extraction procedure has been established for chromium speciation in natural water samples prior to determination by atomic absorption spectrometry. The procedure is based on the solid phase extraction of the Cr(VI)- Dowex M 4195 chelating resin. After oxidation of Cr(III) to Cr(VI) by using H2O2, the presented method was applied to the determination of the total chromium. The level of Cr(III) is calculated by difference of total chromium and Cr(VI) levels. The procedure was optimized for some analytical parameters including pH, eluent type, flow rates of sample and eluent, matrix effects, etc. The presented method was applied for the speciation of chromium in natural water samples with satisfactory results (recoveries >95%, RSDs <10%). In the determinations of chromium species, flame atomic absorption spectrometer was used. The results were checked by using NIST SRM 2711 Montana soil and GBW 07603 Bush branched and leaves.

Chromium Speciation Using an Aminated Amberlite XAD-4 Resin Column Combined with Microsample Injection-Flame Atomic Absorption Spectrometry.

Amberlite XAD-4 resin (AXAD-4) was chemically modified to an aminated Amberlite XAD-4 (AAXAD-4) resin and characterized by infrared spectroscopy. AAXAD-4 resin was used as an efficient solid phase for the preconcentration and speciation of Cr(III) and Cr(VI) ions by column technique. The concentration of chromium species was determined by microsample injection system-flame atomic absorption spectrometer (MIS-FAAS). Selective retention of Cr(III) ions was achieved at pH 8.0 and eluted using 1.0 mL of 3.0 mol L-1 HCl and 1.0 mL of 2.0 mol L-1 NaOH, successively, at the flow rate of 5.0 mL min-1. The maximal sorption capacity of AAXAD-4 resin for Cr(III) ions was found to be 67.0 mg g-1. The limit of detection (LOD) and limit of quantitation (LOQ) for Cr(III) ions were found to be 0.041 and 0.131 ∆g L-1, respectively, with preconcentration factor (PF) of 375 and relative standard deviation (RSD) of 3.75% (n = 11). The method was validated using certified reference materials (CRMs) and successfully applied to the real samples, spiked with Cr(III) and Cr(VI) ions.

The effects of air pollution and smoking on placental cadmium, zinc concentration and metallothionein expression.

This study is designed to determine the placental zinc (Zn) and cadmium (Cd) levels in mothers who were smokers, mothers who were thought to be exposed to air pollution, and mothers who were non-smokers and to investigate the relationship between the expression of placental metallothionein (MT) binding these metals and blood progesterone level. Placental Zn and Cd levels were measured by atomic absorption spectrometry. Presence of placental MT was determined immunohistochemically. Placental changes were examined by light microscope after H&E and PAS staining. Immunohistochemical MT staining of syncytiotrophoblastic and villous interstitial cells were scored as positive or negative. Among the 92 mothers included in the study, 33 were smokers (Group I), 29 had been exposed to air pollution (Group II) and 30 were non-smoker rural residents who had never been exposed to air pollution (Group III). Mean off-spring birth weight of 3198.62+/-380.01 g and mean placenta weight of 561.38+/-111.55 g of Group II were lower when compared with those of other two groups. In Group I, mean placental Cd and Zn were 0.063+/-0.022 microg/g and 39.84+/-15.5 microg/g, respectively, being higher than in other groups. In Group II, mean placental Cd and Zn levels were higher than those of Group III. Blood progesterone levels of subjects in Group I (121 ng/ml) were the lowest of all groups. While the mean count of villi was the highest in Group III; the highest mean count of syncytial knots was in Group II. Thickening of vasculo-syncytial membrane was most prominent in Group I. Similarly, MT staining was positive and very dense in 72.7% (24/33) of cases in Group I (p

Solid-phase extraction of Fe(III), Pb(II) and Cr(III) in environmental samples on amberlite XAD-7 and their determinations by flame atomic absorption spectrometry.

This paper describes a simple and accurate procedure for preconcentration of trace amounts of Fe(III), Pb(II) and Cr(III) ions. The preconcentration procedure is based on retention of p-xylenol blue chelates on Amberlite XAD-7. The analytes retained were eluted from Amberlite XAD-7 by using 1 mol L(-1) HCl. The influences of the analytical parameters including amounts of reagents, pH and type of eluent were also investigated. The detection limits of Fe, Pb and Cr were found to be 3.07, 18.6 and 3.27 microg L(-1), respectively. The accuracy of the procedure was checked by the analysis of an electrolytic copper wire sample. The relative error was less than 5%. The presented method was applied to the determination of Fe(III), Pb(II) and Cr(III) in water samples from Denizli, Turkey with good results such as recoveries more than 95%, relative standard deviations below 10%.

Preconcentration of Pb(II), Cr(III), Cu(II), Ni(II) and Cd(II) ions in environmental samples by membrane filtration prior to their flame atomic absorption spectrometric determinations.

A method for separation-preconcentration of Pb(II), Cr(III), Cu(II), Ni(II) and Cd(II) ions by membrane filtration has been described. The method based on the collection of analyte metal ions on a cellulose nitrate membrane filter and determination of analytes by flame atomic absorption spectrometry (FAAS). The method was optimized for several parameters including of pH, matrix effects and sample volume. The recoveries of analytes were generally in the range of 93-100%. The detection limits by 3 sigma for analyte ions were 0.02microgL(-1) for Pb(II), 0.3microgL(-1) for Cr(III), 3.1microgL(-1) for Cu(II), 7.8microgL(-1) for Ni(II) and 0.9microgL(-1) for Cd(II). The proposed method was applied to the determination of lead, chromium, copper, nickel and cadmium in tap waters and RM 8704 Buffalo River Sediment standard reference material with satisfactory results. The relative standard deviations of the determinations were below 10%.

Separation and enrichment of gold(III) from environmental samples prior to its flame atomic absorption spectrometric determination.

A simple and accurate method was developed for separation and enrichment of trace levels of gold in environmental samples. The method is based on the adsorption of Au(III)-diethyldithiocarbamate complex on Amberlite XAD-2000 resin prior to the analysis of gold by flame atomic absorption spectrometry after elution with 1 molL(-1) HNO3 in acetone. Some parameters including nitric acid concentration, eluent type, matrix ions, sample volume, sample flow rate and adsorption capacity were investigated on the recovery of gold(III). The recovery values for gold(III) and detection limit of gold were greater than 95% and 16.6 microgL(-1), respectively. The preconcentration factor was 200. The relative standard deviation of the method was <6%. The adsorption capacity of the resin was 12.3 mg g(-1). The validation of the presented procedure was checked by the analysis of CRM-SA-C Sandy Soil certified reference material. The presented procedure was applied to the determination of gold in some environmental samples.

Solid-phase extraction of Mn(II), Co(II), Ni(II), Cu(II), Cd(II) and Pb(II) ions from environmental samples by flame atomic absorption spectrometry (FAAS).

A new method using a column packed with Amberlite XAD-2010 resin as a solid-phase extractant has been developed for the multi-element preconcentration of Mn(II), Co(II), Ni(II), Cu(II), Cd(II), and Pb(II) ions based on their complex formation with the sodium diethyldithiocarbamate (Na-DDTC) prior to flame atomic absorption spectrometric (FAAS) determinations. Metal complexes sorbed on the resin were eluted by 1 mol L(-1) HNO3 in acetone. Effects of the analytical conditions over the preconcentration yields of the metal ions, such as pH, quantity of Na-DDTC, eluent type, sample volume and flow rate, foreign ions etc. have been investigated. The limits of detection (LOD) of the analytes were found in the range 0.08-0.26 microg L(-1). The method was validated by analyzing three certified reference materials. The method has been applied for the determination of trace elements in some environmental samples.

A multi-element solid-phase extraction method for trace metals determination in environmental samples on Amberlite XAD-2000.

A method for the preconcentration of some transition elements at trace level was proposed using a column filled with Amberlite XAD-2000 resin. Metal ions were adsorbed on XAD-2000 as their diethyldithiocarbamate chelates, then analytes retained on the resin were eluted by 1 mol L(-1) nitric acid in acetone and determined by flame atomic absorption spectrometry (FAAS). The influences of some analytical parameters including pH of sample solution, ligand amount, the type, concentration and volume of elution solution, flow rates of the sample and eluent solutions, adsorption capacity of the resin and sample volume on the preconcentration efficiency have been investigated. The influences of some matrix elements were also examined. The detection limit (N=20, 3 sigma) for Mn(II), Fe(II), Co(II), Cu(II), Cd(II), Zn(II), Pb(II) and Ni(II) were found as 0.20, 0.35, 0.25, 0.20, 0.20, 0.15, 0.45 and 0.25 microg L(-1), respectively. The validation of the procedure was carried out by analysis of certified reference materials. The proposed method was applied to natural waters and kale vegetable (Brassica oleracea var. acephala).

Solid Phase Extraction Preconcentration Method for Simultaneous Determination of Cadmium, Lead, and Nickel in Poultry Supplements.

A new simple, selective, and economical preconcentration method was developed for the determination of Cd, Pb, and Ni in poultry antibiotics and supplements. The proposed preconcentration procedure is based on SPE using 8-hydroxyquinoline and Amberlite IRC-50 resin as complex and adsorbent, respectively. The determination was carried out by microsample injection system (MIS) flame atomic absorption spectroscopy (FAAS). Several analytical parameters were examined, including pH, type of resin, amount of resin, type of eluent, eluent volume, flow rate, sample volume, and interference of diverse ions. Under optimum experimental conditions, LODs and LOQs were 0.017 and 0.055, 0.016 and 0.53, and 0.074 and 0.248 µg/L for Cd, Pb, and Ni, respectively, with RSDs < 2.50%. The accuracy of SPE-MIS-FAAS was successfully tested by the standard addition method, with obtained recoveries >99%. The proposed method was successfully applied for the determination of Cd, Pb, and Ni in poultry supplement and antibiotic samples.

Trace metal pollution from traffic in Denizli-Turkey during dry season.

OBJECTIVE: To determine the metal contents of date palm (Pheonix dactylifera) samples in dry season from Denizli-Turkey for investigation of heavy metal-polluted traffic. METHOD: The levels of iron, copper, zinc, lead, cadmium, nickel, chromium, and manganese ions in the leaves of thirty five date palm (Pheonix dactylifera) samples collected from various levels of traffic in the streets of Denizli-Turkey were determined by graphite furnace or flame atomic absorption spectrometry. The wet, dry, and microwave digestion procedures for the date palm (Pheonix dactylifera) leaves were compared. The accuracy of the digestion procedures was checked using a standard reference material (IAEA-336 Lichen, SRM). RESULTS: Microwave digestion procedure for the leaves was preferred because it was more proper with respect to both time and recovery than dry and wet digestion. The levels of the heavy metal ions investigated were the highest on the samples from high traffic level. Also correlations between metal levels and traffic volume for all the metals were investigated. CONCLUSION: In the light of our findings, the date palm (Phoenix dactylifera) leaves are suitable as a biomonitor for atmospheric heavy metal-polluted traffic. Significant correlations can be obtained between traffic levels and heavy metal concentrations.

Using of atomic absorption spectrometry for diagnosis of electrical injuries (an experimental rat study).

The diagnosis of electrical injuries may be difficult and sometimes we should use some methods to support that. In this experimental rat study; electrical injuries were made in the dorsal skin of rats using 110 V, 100 A ac current. Swabs were taken from these injuries and investigated for iron and copper by using atomic absorption spectrometry. There was a great significance between study and control groups for copper (p<0.01). It was suggested that metallic deposition to skin in electrical injuries can be shown by atomic absorption spectrometry as quantitatively and can be used for improving the diagnostic sensitivity of electrical lesions.