Separation of Boron from Geothermal Waters with Membrane System.

This study presents the separation and recovery of boron from geothermal waters with a polymeric membrane system and suggests a transport mechanism. The optimum relative parameters of the transport were examined. The recovery value of boron was 60.46% by using polymeric membrane system from prepared aquatic solution to the acceptor phase. The membrane's capacity and selectivity of the transport process were examined. Kinetics values were calculated for each transport parameter. The optimum kinetic values were 1.4785 × 10-6 (s-1), 7.3273 × 10-8 (m/s), 13.5691 × 10-8 (mol/m2.s), 5.8174 × 10-12 (m2/s) for constant rate, permeability coefficient, flux, and diffusion coefficient, respectively. Boron was transported selectively and successfully from geothermal waters in the presence of other metal cations with 59.85% recovery value. This study indicates the application of real samples in polymeric membrane systems, which are very practical, economic, and easy to use for large-scale applications. The chemical and physical properties of polymer inclusion membranes (PIMs) offer the opportunity to be specially designed for specific applications.

Determination of four priority polycyclic aromatic hydrocarbons (4PAHs) by GC-MS in traditional Turkish yoghurts.

Polycyclic aromatic hydrocarbons (PAHs) are ingested with foods and cause toxicities for humans. Yoghurt is one of the main foods that mediate PAH ingestion. Yanik yoghurt, a traditional strained yoghurt, can contain PAHs due to its production process. Therefore, the concentration and types of four polycyclic aromatic hydrocarbons were determined by gas chromatography-mass spectrometry (GC-MS). Yanik yoghurt samples were collected from different shops in Denizli, Turkey. For the method validation, the Eurachem guide (second edition) was adopted. Accordingly, linearity, working range, limits of detection (LOD), quantification (LOQ), precision and trueness values were set. Due to the selected validation parameters, the limit for detection was between 0.03 ng g-1and 0.05 ng g-1while the limit for quantification was between 0.10 ng g-1 and 0.16 ng g-1. Recovery rates higher than 83.80 % were obtained for four PAHs at two spiked concentrations (2.0 and 5.0 ng g-1). Five Yanik yoghurt samples and one commercial concentrated yoghurt sample were successfully analysed using the validated method.

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%.

Single-laboratory validation of a saponification method for the determination of four polycyclic aromatic hydrocarbons in edible oils by HPLC-fluorescence detection.

An analytical method is reported for the determination of four polycyclic aromatic hydrocarbons (benzo[a]pyrene (BaP), benz[a]anthracene (BaA), benzo[b]fluoranthene (BbF) and chrysene (CHR)) in edible oils (sesame, maize, sunflower and olive oil) by high-performance liquid chromatography. Sample preparation is based on three steps including saponification, liquid-liquid partitioning and, finally, clean-up by solid phase extraction on 2 g of silica. Guidance on single-laboratory validation of the proposed analysis method was taken from the second edition of the Eurachem guide on method validation. The lower level of the working range of the method was determined by the limits of quantification of the individual analytes, and the upper level was equal to 5.0 µg kg(-1). The limits of detection and quantification of the four PAHs ranged from 0.06 to 0.12 µg kg(-1) and from 0.13 to 0.24 µg kg(-1). Recoveries of more than 84.8% were achieved for all four PAHs at two concentration levels (2.5 and 5.0 µg kg(-1)), and expanded relative measurement uncertainties were below 20%. The performance of the validated method was in all aspects compliant with provisions set in European Union legislation for the performance of analytical methods employed in the official control of food. The applicability of the method to routine samples was evaluated based on a limited number of commercial edible oil samples.

Ion pair-dispersive liquid-liquid microextraction coupled to microsample injection system-flame atomic absorption spectrometry for determination of gold at trace level in real samples.

A novel ion pair-dispersive liquid-liquid microextraction (IP-DLLME) of gold followed by its determination with microsample injection system-flame atomic absorption spectrometry (MIS-FAAS) detection was developed. The extraction method was based on the reaction of anionic tetrachloro gold(III) complex with the cationic form of Rhodamine B to give a violet ion pair complex, which is extracted from 1.0 mol L(-1) HCl solution of 8.0 mL to fine droplets of chloroform of 500 µL. A Plackett-Burman experimental design of MINITAB statistical program was employed to optimize the influence of main parameters to be controlled in DLLME. After optimizing the extraction conditions, gold was quantitatively recovered by preconcentration factor of 40, limit of detection (LOD) of 1.8 µg L(-1) and relative standard deviation of less than 6.8%. The proposed method was successfully applied to the preconcentration and determination of gold in some samples such as tap water, waste water, copper electrolysis solution and copper wire coated nickel.

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 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.

Selective extraction of chromium(VI) using a leaching procedure with sodium carbonate from some plant leaves, soil and sediment samples.

Speciation of chromium in some plant leaves, soil and sediment samples was carried out by selective leaching of Cr(VI) using a sodium carbonate leaching procedure. Total chromium from the samples was extracted using aqua regia and oxidative acid digestion, respectively. The concentrations of chromium species in the extracts were determined using by graphite furnace atomic absorption spectrometry (GFAAS). Uncoated graphite furnace tubes were used as an atomizer. Due to the presence of relatively high amounts of Na(2)CO(3) in the resulting samples, the possible influences of Na(2)CO(3) on the absorbance signals were checked. There is no interference of Na(2)CO(3) on the chromium absorbance up to 0.1 mol L(-1) Na(2)CO(3). A limit of detection (LOD) for determination of Cr(VI) in 0.1 Na(2)CO(3) solution by GFAAS was found to be 0.93 microg L(-1). The procedure was applied to environmental samples. The relative standard deviation, R.S.D. as precision for 10 replicate measurements of 20 microL(-1) Cr in processed soil sample was 4.2%.

Factorial design for multivariate optimization of preconcentration system for spectrophotometric phosphorus determination.

The present paper proposes a preconcentration procedure for phosphorus determination by using ultraviolet-visible spectrophotometer. It is based on the formation of phosphomolybdate and its reduction to molybdenum blue. Phosphorus extraction as phosphomolybdenum blue complex was performed onto Amberlite XAD-4. The optimization step was carried out using two-level full factorial design. Three variables (resin amount, sample volume, flow rate) were regarded as factors in the optimization. The relative standard deviation was 2% at 0.08 microg mL(-1). The limit of detection was found to be 2.23 microg L(-1) (N=15). The proposed solid-phase extraction procedure was applied to phosphorus in some fruit leaves, natural waters, and a standard reference material (SRM 1515 apple leaves).

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%.

Determining the heavy metal pollution in Denizli (Turkey) by using Robinio pseudo-acacia L.

The leaves of Robinia pseudo-acacia L. (Fabaceae) were evaluated as a biomonitors of heavy metal contamination in Denizli city, Turkey. Concentrations of Fe, Zn, Pb, Cu, Mn and Cd were determined in washed and unwashed leaves and soils collected from a wide range of sites with different degrees of metal pollution (industry, urban roadside, suburban) and from a rural (control) site by atomic absorption spectrometry. All the elements that measured were found to be at high levels in samples collected at industrial sites, except for lead and copper which were found at high levels in samples collected from urban roadsides that associated with the road traffic. The strong correlation between the degree of contamination and concentrations in all plant leaves assessed display that the leaves of R. pseudo-acacia reflect the environmental changes accurately, and that they seem as an effective biomonitor of environmental quality in areas subjected to industrial and traffic pollutions.