The effect of 10 weeks of karate training on the development of motor skills in children who are new to karate.

This study investigated the effect of a 10-week karate training program on the motor skill development of 5-7-year-old children new to karate with two different test batteries. A total of 28 participants were included in the study: 18 in the Karate group and 10 in the control group. The karate group was subjected to a fundamental karate training (kihon) program consisting of 90-minute sessions four days a week for ten weeks in addition to physical education classes at their schools. In contrast, the control group did not participate in any sportive activities except physical education classes in their schools. Data were collected using the Eurofit test battery and the TGMD-2 test. In the pre-post test comparison of the anthropometric measurements of the karate group, no significant difference was found in the control group. In contrast, a significant difference was obtained in height, body mass index, and body fat percentage. In the post-test analysis of the two independent groups, there were statistically significant differences in favor of the karate group regarding height and body fat percentage (p < 0.005). In the pre-post analysis of the Eurofit test and the TGMD-2 for the karate group, all parameters showed statistically significant improvements (p < 0.001), while the control group showed no statistical difference. After comparing the karate and control groups, the Eurofit Test and TGMD-2 post-test results showed significantly higher scores (statistically significant differences) in all parameters for the karate group. In conclusion, the study shows that the 10-week karate training program positively affected the motor development of the participating children.

Important role of pore-filling mechanism in separating naproxen from water by micro-mesoporous carbonaceous material.

Commercial micro-mesoporous carbonaceous material (MCM; 56.8% mesopores) was applied for investigating the removal phenomenon of naproxen drug in aqueous solutions through batch adsorption experiments. Results demonstrated that the adsorption capacity of MCM to naproxen was slightly affected by different pHeq (2.0-11) and ionic strength (0-1 M NaCl). Adsorption kinetics, isotherms, thermodynamics, and mechanisms were evaluated at pH 7.0. Adsorption kinetics indicated the rate constants for adsorption (0.2 × 10-3  L/(mg × min) and desorption (0.076/min) and the adsorption equilibrium constant (2.6 × 10-3  L/mg). Adsorption isotherm showed that MCM exhibited a high-affinity adsorption capacity to naproxen (even at low concentrations) and its Langmuir maximum adsorption capacity (Qmax ) was 252.7 mg/g at 25°C. Adsorption thermodynamics proved that the adsorption process was endothermic and physisorption (ΔH° = 9.66 kJ/mol). The analysis result of pore size distribution demonstrated that the internal pore structure of MCM was appropriate for adsorbing naproxen molecules. Pore-filing mechanism (pore diffusion phenomenon) was confirmed by a considerable decrease in BET-surface area (585 m2 /g) and total pore volume (0.417 cm3 /g) of MCM after adsorbing naproxen (~1000 mg/L and pH 7.0) at 5 min (341 and 0.256), 60 min (191 and 0.205), 120 min (183 and 0.193), 360 min (144 and 0.175), and 24 h (71.6 m2 /g and 0.123 cm3 /g, respectively). The pore diffusion occurred rapidly (even at the initial adsorption period of 5 min). The FTIR technique was applied to identify the existence of C-H···π and n-π interaction. π-π interaction (evaluated through ID /IG ratio and C=C band) played a minor contribution in adsorption mechanisms. The ID /IG ratio (determined by the Raman technique) of MCM before adsorption (1.195) was similar to that after adsorption (1.190), and the wavenumber (C=C band; its FTIR spectrum) slightly shifted from 1638 to 1634 cm-1 after adsorption. A decrease in the Qmax value of MCM from 249 to 217 (H2 O2 -oxidized MCM) or to 224 mg/g (HNO3 -oxidized MCM) confirmed the presence of π-π interaction. Electrostatic attraction was a minor contribution. MCM can serve as a promising material for removing naproxen from water environment through a pore-filling mechanism. PRACTITIONER POINTS: Pore-filling mechanism was proposed by comparing textural properties of MCM before and after adsorbing naproxen. C-H···π and n-π interactions were identified via FTIR technique. π-π interaction was observed by FTIR and Raman techniques. Oxidation of MCM with HNO3 or H2 O2 was a helpful method to explore π-π interaction. Electrostatic attraction was explained through studies: effects of pH and NaCl along with desorption.

Removal of Ni(II), Cu(II), Pb(II), and Cd(II) from Aqueous Phases by Silver Nanoparticles and Magnetic Nanoparticles/Nanocomposites.

The intake of heavy metals into the body, even at very low concentrations, may cause a decrease in central nervous system functions; deterioration of blood composition; and liver, kidney, and lung damage. Therefore, heavy metal ions must be removed from water. In this study, silver, magnetic iron/copper, and iron oxide nanoparticles were synthesized using Lathyrus brachypterus extract and then Fe/Cu-AT, Fe3O4-AT, Fe/Cu-CS, and Fe3O4-CS magnetic nanocomposite beads were synthesized using alginate and chitosan. The removal of Cd(II), Pb(II), Ni(II), and Cu(II) ions from aqueous phases using synthesized nanoadsorbents was investigated by single and competitive (double and quaternary) adsorption techniques. The kinetic usability of the magnetic iron oxide chitosan (Fe3O4-CS) nanocomposite beads with the highest removal efficiency was evaluated. Based on experimental results, the order of removal was found to be 98.39, 75.52, 51.54, and 45.34%, and it was listed as Pb(II) > Cu(II) > Cd(II) > Ni(II), respectively. The Dubinin-Radushkevich, Freundlich, Langmuir, and Temkin isotherm models were used, and experimental results revealed that the experimental data fit the Langmuir model better. The maximum adsorption capacities (qm) obtained from the Langmuir isotherm model of Fe3O4-CS were found to be 8.71, 23.75, 18.57, and 12.38 mg/g for Ni(II), Pb(II), Cu(II), and Cd(II) ions, respectively. When the kinetic data were applied to the Lagergren, Ho-McKay, and Elovich models, it was observed that the adsorption kinetics mostly conformed to the Ho-McKay second-order rate equation. The binary and quaternary competitive adsorption data showed that Fe3O4-CS were selective toward Cu(II) and Pb(II). The reusability of the Fe3O4-CS nanoadsorbent was performed as three cycles with the same concentration. The adsorption capacities were found to be 95.81, 70.65, 50.50, and 42.75%, in turn for Pb(II), Cu(II), Cd(II), and Ni(II) ions after three cycles, which revealed that the Fe3O4-CS nanoadsorbent can be used after three cycles without losing its efficiency.

Antibacterial and antibiofilm efficacy of colistin & meropenem conjugated silver nanoparticles against Escherichia coli and Klebsiella pneumoniae.

The progressive increase in infections caused by multidrug-resistant (MDR) Gram-negative bacteria and the emergence of resistance to last-resort antimicrobial drugs in recent years necessitate the development of new therapeutic strategies. This study was conducted to obtain nanostructured antimicrobials by conjugating colistin (COL) and meropenem (MEM) antibiotics with biosynthesized silver nanoparticles (bio-AgNPs) via the green synthesis method using Rosa damascena extract, and to investigate the antibacterial and antibiofilm activity of these nanostructures against Escherichia coli and Klebsiella pneumoniae strains. Ultraviolet-visible spectrophotometry, high-resolution-transmission electron microscopy, atomic force microscopy, X-ray diffraction, and Fourier transform-infrared spectroscopy analyses were performed to determine the physical and chemical properties of synthesized bio-AgNPs, COL@bio-AgNPs, MEM@bio-AgNPs, and COL&MEM@bio-AgNPs. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration of nanoparticles were determined on standard and MDR clinical strains. The antibiofilm efficacy and cytotoxic effect of nanoparticles were evaluated by the crystal violet dye method and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide dye method, respectively. The characterization analyses demonstrated that the synthesized nanoparticles had crystal structure and spherical morphology (5.6-30.2 nm in size). Antibiotic conjugated nanoparticles exhibited better antimicrobial activity and lower MIC values (0.125-4 µg/mL) on the tested strains compared to free antibiotics, and MIC values were decreased up to 1024-fold (p < 0.05). Antibiotic conjugated nanoparticles were found to be more effective in biofilm eradication than free antibiotics and bio-AgNPs and had a less inhibitory effect on peripheral blood mononuclear cell viability. The findings revealed that antibiotic-conjugated nanoparticles have the potential to be used as an effective antimicrobial drug against MDR E. coli and K. pneumoniae strains.

Effect of 6-week karate (kihon) and basic movement exercise on balance performance in visually impaired individuals.

Today, the participation of visually impaired individuals in sports activities is essential. Because the ability to move independently starts to develop with a delay in visually impaired individuals, physical activity is necessary to compensate for developmental delay, eliminate the problem of independent movement in social life by reducing obstacle perception problems, develop self-confidence, and provide regular muscle activation and motivation to move. The study investigated the effect of 6 weeks of karate (kihon) and basic movement training on balance performance in individuals with congenital visual impairment. Fifteen visually impaired individuals aged between 10 and 14 participated in the study, and three groups were formed: experiment 1, experiment 2, and the control group. After the pre-tests were taken, the experimental groups received karate and basic movement training in addition to physical education classes for 6 weeks, while the control group received only physical education classes. When the study results were examined, there were highly significant differences between the pre- and post-test values of the groups receiving karate and basic movement training. At the same time, no progress was observed in the control group. In the post-test comparison of the karate and control groups, positive significance was found in the values of the karate group. In the same way, in the post-test comparison of the basic movement training group and the control group, positive progress was made in the basic movement training group. The post-test comparison of the basic movement training and karate groups was the same. As a result, it was concluded that basic movement training and karate exercises applied for 6 weeks positively affected the balance development in visually impaired individuals aged 10-14 years. No difference was found between the exercise protocols regarding effectiveness, and no improvement was observed in individuals who did not participate in any exercise.

Examination of basic motor skills in children and adolescents.

Aim of the study: The aim of this study was the investigation of basic motor skills in 5-14-year-old boys and girls. Materials and Methods: A total of 842 primary school children, 421 boys and 421 girls, participated in the study. 13.3% of the participants were 5-6 years old, 29.5% were 7-8 years old, 21.5% were 9-10 years old, 16.4% were 11-12, and 19.4% were 13-14 years old. The balance skills of the participants were measured with the (Körperkoordinationstest für Kinder) KTK test. Findings: When the classification of children according to KTK defining classes is examined, 40.7% are very good. When the children's KTK Backward Balancing scores were examined, a statistically significant difference was found between gender and age groups (p < 0.05). Girls between the ages of 5-6 and 7-8 years had a higher score for KTK backward balance. KTK Total scores were examined according to the Body Mass Index groups, when the total scores of KTK were compared, the lowest scores were in the obese group. Conclusion: According to the study results, age is an essential factor for balance skills. As the age increased, the overall scores of the KTK increased. It was determined that girls' KTK backward balancing scores were higher than boys. According to BMI results, the balance performances of obese children were found to be lower than the other groups. This difference can be explained by the negative effect of obesity in this age group. According to these results, it may be recommended to observe and improve the balance performances of obese children.

The Combined Contribution of Fear and Perceived Danger of COVID-19 and Metacognitions to Anxiety Levels during the COVID-19 Pandemic.

Despite a wide base of research suggesting a major role for dysfunctional metacognitions in contributing to anxiety, their role in explaining psychological distress in the context of the COVID-19 pandemic remains unclear. In this study we investigated whether metacognitions would predict anxiety, while controlling for fear and perceived danger of COVID-19. A total of 862 individuals were included in this study. Participants completed sociodemographic questions, emotional state questions relating to COVID-19, the Metacognitions Questionnaire-30, and the Generalized Anxiety Disorder-7. Results showed that both negative beliefs about thoughts concerning uncontrollability and danger, and cognitive self-consciousness were significant predictors of anxiety beyond the fear and perceived danger of COVID-19. Future studies involving clinical populations are needed to investigate the longer-term impact of metacognitions in the maintenance and exacerbation of anxiety associated with the fear and perceived danger of COVID-19.

Correction to: The Combined Contribution of Fear and Perceived Danger of COVID 19 and Metacognitions to Anxiety Levels during the COVID 19 Pandemic.

[This corrects the article DOI: 10.1007/s10942-021-00429-9.].

Peanut shells-derived biochars prepared from different carbonization processes: Comparison of characterization and mechanism of naproxen adsorption in water.

The ubiquitous appearance of nonsteroidal anti-inflammatory drugs (i.e., naproxen) in water bodies has raised enormous concerns among general public. Development of promising materials for eliminating such contaminants from water environment has attracted much attention in the scientific community. In this study, three (direct, post-treated and pre-treated) methods were developed to prepare biochars (800-PSB, 800-800-PSB, and 190-800-PSB, respectively) derived from the wastes of peanut shells (PS). They were thoroughly characterized by various important properties (i.e., porosity and superficial functional group) and applied to remove naproxen drug from water. Results indicated that although the pre- and post-treatments had a slight effect on the surface area of biochars (i.e., 571 m2/g for 800-PSB, 596 m2/g for 800-800-PSB, and 496 m2/g for 190-800-PSB), such treatments remarkably improved the adsorption capacity of biochar. The maximum adsorption capacity of biochar (obtained from the Langmuir model) towards naproxen in solution at 25 decreased in the following order: 800-800-PSB (324 mg/g) > 190-800-PSB (215 mg/g) > 800-PSB (105 mg/g). The thermodynamic study demonstrated that the adsorption was spontaneous and exothermic. Depending the preparation process, the contribution of each mechanism in the adsorption process was dissimilar. The overall adsorption mechanism was regarded as pore filling, π-π interaction, hydrogen bonding formations, n-π interaction, van der Waals force, and electrostatic attraction. Two methods used to identify the important role of π-π interaction were proposed herein. The possible desorption and reuse of laden-biochars were investigated by the chemical and thermal methods. The prepared biochar samples can serve as potential carbonaceous porous adsorbents for effectively removing naproxen from water media.

Ultrasonic Gas Sensing by Two-Dimensional Surface Phononic Crystal Ring Resonators.

An acoustic ring resonator employing a two-dimensional surface phononic crystal is proposed for high-sensitivity detection in binary gas mixtures. Band analyses and frequency-domain simulations via the finite-element method reveal that a single band for spoof surface acoustic waves appears at ultrasonic frequencies around 58 kHz where modification of its dispersion due to varying gas composition results in a linear shift of the resonance frequency. The shift rate is -17.3 and 8.8 mHz/ppm for CO2 and CH4, respectively. The linear shift of resonance frequency is experimentally validated. In addition, the ring resonator can also be employed to track acoustic intensity variation with gas concentration, where exponentially decaying intensity for low concentrations leverages high-sensitivity operation.

Efficient removal of anti-inflammatory from solution by Fe-containing activated carbon: Adsorption kinetics, isotherms, and thermodynamics.

This work developed an innovative activated carbon (ICAC) derived from orange peels (OP) through chemical activation using FeCl3. The traditional activated carbon (PCAC) that was prepared through K2CO3 activation served as a comparison. Three adsorbents (ICAC, PCAC, and OP) were characterized by various techniques, these being: Brunauer-Emmett-Teller (BET) surface area analysis, thermo-gravimetric analysis, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. They were applied to remove diclofenac from aqueous solution applying batch experiments, in order to investigate the characteristics of adsorptive kinetics, isotherms, and thermodynamics. Results indicated that the SBET values were in the following order: 457 m2/g (PCAC) > 184 m2/g (ICAC) > 3.56 m2/g (OP). The adsorption process reached a fast equilibrium, with activating energies being 27.6 kJ/mol (ICAC), 16.0 kJ/mol (OP), and 11.2 kJ/mol (PCAC). The Langmuir adsorption capacities at 30 °C exhibited the decreasing order: 144 mg/g (ICAC) > 6.44 mg/g (OP) > 5.61 mg/g (PCAC). The thermodynamic parameters demonstrated a signal dissimilarity between biosorbent (ΔG° <0, ΔH° <0, and ΔS° <0) and activated carbon samples (ΔG° <0, ΔH° >0, and ΔS° >0). The presence of iron (FeOCl, γ-Fe2O3, and FeOOH) on the surface of ICAC played a determining role in efficiently removing diclofenac from solution. The excellent adsorption capacity of ICAC toward diclofenac resulted presumably from the contribution of complicated adsorption mechanisms, such as hydrogen bonding, ion-dipole interaction, π-π interaction, pore filling, and possible Fenton-like degradation. Therefore, FeCl3 can serve as a promising activating agent for AC preparation with excellent efficiency in removing diclofenac.

Separation and Preconcentration of Nickel(II) from Drinking, Spring, and Lake Water Samples with Amberlite CG-120 Resin and Determination by Flame Atomic Absorption Spectrometry.

In this study, Amberlite CG-120 adsorbent was used for the separation/preconcentration of Ni(II) ions in commercial drinking, spring and lake water samples before detection by flame atomic absorption spectrometry. Various optimization parameters for Ni(II) determination, such as pH, eluent type and concentration, sample and eluent flow rates, amount of adsorbent, were investigated to obtain better sensitivity, accuracy, precision and quantitative recovery. Furthermore, the interference effects of some ions on the recovery efficiency of Ni(II) were also investigated. The optimum experimental parameters were obtained in the case of pH 1; 5 mL of 4 mol L-1 HCl for eluent and 0.3 g for the adsorbent amount. The limit of detection was found to be 0.58 µg L-1 and linearity ranged from 5 to 50 µg L-1. The accuracy of the method was tested by the certified reference material of TMDA-70.2 Ontario Lake Water at a 95% confidence level.

Determination of Sulfur in Grape and Apricot Samples Using High-resolution Continuum Source Electrothermal Molecular Absorption Spectrometry.

The determination of sulfur in apricot and grape samples was performed by using high-resolution continuum source electrothermal molecular absorption spectrometry based on vaporization of the carbon monosulfide (CS) molecule. CS forms in the gas phase without the addition of any molecule-forming element, since graphite cuvette contains plenty of carbon as well as food samples. A mixture of 15 µg Pd + 10 µg Mg was used in solution as the chemical modifier. The best sensitivity was obtained at 900°C of the pyrolysis temperature with a K2SO4 calibration solution. The calibration plot drew a linear path between 50 and 1600 ng of sulfur, and the limit of detection was found to be 23 ng. The accuracy of the method was confirmed with the use of a standard reference material (Rice Flour, NIST SRM 1568a). The sulfur content in chemically dried apricot samples (1987 ± 45 mg/kg) was determined to be higher than that of apricot samples dried under sunshine.

A Novel Method Using Solid-Phase Extraction with Slotted Quartz Tube Atomic Absorption Spectrometry for the Determination of Manganese in Walnut Samples.

Mn(2+) was separated and preconcentrated using both solid-phase extraction (SPE) and a slotted quartz tube (SQT), and detected by a flame atomic absorption spectrometry (FAAS) system. Firstly, Mn(2+) was retained on a column filled with Amberlite CG-120 resin, and then retained Mn(2+) ions on the Amberlite CG-120 resin eluted with 5 mL of 4 mol/L HNO3. This part was called the "first preconcentration step". Furthermore, to determine the Mn(2+) in a walnut sample, the SQT device was also used after the separation and preconcentration of Mn(2+) from the Amberlite CG-120 resin so as to further improve the sensitivity of system. This part was called the "second preconcentration step" in this study. The enrichment factor and limit of detection values were found to be 360 fold and 0.22 µg/L, in turn, after a two-step preconcentration method. The good accuracy of method was confirmed with the use of standard reference material (spinach leaves, NIST-1570a).

Tellurium speciation analysis using hydride generation in situ trapping electrothermal atomic absorption spectrometry and ruthenium or palladium modified graphite tubes.

Speciation of tellurium can be achieved by making use of different kinetic behaviors of Te(IV) and Te(VI) upon their reaction with sodium borohydride using hydride generation. While Te(IV) can form H(2)Te, Te(VI) will not form any volatile species during the course of hydride formation and measurement by atomic absorption spectrometry. Quantitative reduction of Te(VI) was achieved through application of a microwave assisted prereduction of Te(VI) in 6.0 mol/L HCl solution. Enhanced sensitivity was achieved by in situ trapping of the generated H(2)Te species in a previously heated graphite furnace whose surface was modified using Pd or Ru. Overall efficiency for in situ trapping in pyrolytically coated graphite tube surface was found to be 15% when volatile analyte species are trapped for 60s at 300°C. LOD and LOQ values were calculated as 0.086 ng/mL and 0.29 ng/mL, respectively. Efficiency was increased to 46% and 36% when Pd and Ru surface modifiers were used, respectively. With Ru modified graphite tube 173-fold enhancement was obtained over 180 s trapping period with respect to ETAAS; the tubes could be used for 250 cycles. LOD values were 0.0064 and 0.0022 ng/mL for Pd and Ru treated ETAAS systems, respectively, for 180 s collection of 9.6 mL sample solution.

Indium determination using slotted quartz tube-atom trap-flame atomic absorption spectrometry and interference studies.

Sensitivity enhancement of indium determination by flame atomic absorption spectrometry (FAAS) was achieved; using a slotted quartz tube (SQT-FAAS) and slotted quartz tube atom trap (SQT-AT-FAAS). SQT was used as an atom trap (AT) where the analyte is accumulated in its inner wall prior to re-atomization. The signal is formed after re-atomization of analyte on the trap surface by introduction of 10 µL of isobutyl methyl ketone (IBMK). Sensitivity was improved 400 times using SQT-AT-FAAS system with respect to conventional FAAS and 279 times with respect to SQT-FAAS without any collection. Characteristic concentration (C(0)) and limit of detection values were found to be 3.63 ng mL(-1) and 2.60 ng mL(-1), respectively, using a sample flow rate of 7.0 mL min(-1) and a collection period of 5.0 min. In addition, interference effects of some elements on indium signal were studied. In order to characterize indium species trapped, X-ray Photoelectron Spectrometry (XPS) was utilized and it was found that indium was collected on the inner surface of SQT as In(2)O(3). The accuracy of the procedure was checked to determine indium in the standard reference material (Montana Soil, SRM 2710).

Determination of mercury, cadmium, lead, zinc, selenium and iron by ICP-OES in mushroom samples from around thermal power plant in Mugla, Turkey.

Scleroderma verrucosum, Stropharia coronilla, Lactarius deterrimus, Chroogomphus rutilus, Russula delica, Laccaria laccata, Clitocybe odora var. alba, Lyophyllum decastes, Coprinus comatus, Helvella leucomelaena, Melanoleuca cognata, Melanoleuca cognata, Paxina acetabulum, Clitocybe vermicularis, Sarcosphaera crassa, Rhizopogon roseolu and Thelephora caryophyllea were collected from different localities in Mugla-Yatagan region of Turkey. Their trace metals concentrations were determined by ICPOES after microwave digestion. The results were 0.37 ± 0.01-5.28 ± 0.21 for cadmium, 467 ± 19-3,280 ± 131 for iron, 0.69 ± 0.03-9.15 ± 0.37 for lead, 18.70 ± 0.75-67.10 ± 2.68 for selenium, 75 ± 3-213 ± 8 for zinc and 0.15 ± 0.01-0.55 ± 0.01 for mercury (as µg/g). The detection limits for ICPOES were found as 0.25 for Cadmium, 0.2 for iron, 0.1 for lead, 0.5 for selenium, 0.2 for zinc and 0.03 for mercury (as mg L(-1)). The Relatively Standard Deviations (R.S.D.) were found below 4.0%. The accuracy of procedure was confirmed by certified reference material.

Prevalence of prostate cancer in high boron-exposed population: a community-based study.

We investigated the possible relationship between boron exposure and prostate cancer (PCa) for men living and being employed at boron mines in villages with rich boron minerals. Out of 456 men studied, 159 were from villages with rich boron sources and boron levels in drinking water of >1 mg L(-1) and these men formed the study group, while 63 from villages with rich boron sources and boron levels in drinking water of <1 mg L(-1) were enrolled into control group 1. A further 234 subjects from other villages with no boron mines were considered as control group 2. Prostate specific antigen (PSA) levels could be obtained from a total of 423 men. Urinary boron concentration as an indicator of boron exposure in 63 subjects, prostatic volumes by transrectal ultrasonography in 39 subjects, and prostatic biopsies in 36 subjects were obtained for study and control groups. The daily boron exposure was calculated according to urinary boron levels. Although there was no significant difference among the groups in terms of total PSA levels, the number of subjects with tPSA ≥2.5 and tPSA ≥10.0 ng dL(-1) prostatic volumes in men whose prostates were biopsied (p < 0.012) was significantly lower in the study group as compared with those in the control group 2. These results suggested that high exposure to boron might have an implication within the prostatic cellular processes related to hyperplasia and carcinogenesis, even though we did not find a statistically significant association between PCa and boron exposure.

Determination and interference studies of bismuth by tungsten trap hydride generation atomic absorption spectrometry.

The determination of bismuth requires sufficiently sensitive procedures for detection at the microg L(-1) level or lower. W-coil was used for on-line trapping of volatile bismuth species using HGAAS (hydride generation atomic absorption spectrometry); atom trapping using a W-coil consists of three steps. Initially BiH(3) gas is formed by hydride generation procedure. The analyte species in vapor form are transported through the W-coil trap held at 289 degrees C where trapping takes place. Following the preconcentration step, the W-coil is heated to 1348 degrees C; analyte species are released and transported to flame-heated quartz atom cell where the atomic signal is formed. In our study, interferences have been investigated in detail during Bi determination by hydride generation, both with and without trap in the same HGAAS system. Interferent/analyte (mass/mass) ratio was kept at 1, 10 and 100. Experiments were designed for carrier solutions having 1.0M HNO(3). Interferents such as Fe, Mn, Zn, Ni, Cu, As, Se, Cd, Pb, Au, Na, Mg, Ca, chloride, sulfate and phosphate were examined. The calibration plot for an 8.0 mL sampling volume was linear between 0.10 microg L(-1) and 10.0 microg L(-1) of Bi. The detection limit (3s/m) was 25 ng L(-1). The enhancement factor for the characteristic concentration (C(o)) was found to be 21 when compared with the regular system without trap, by using peak height values. The validation of the procedure was performed by the analysis of the certified water reference material and the result was found to be in good agreement with the certified values at the 95% confidence level.