Concentration Of Potassium Iodide Research Articles

The application of flow to an ultrasonic horn system: Phenol degradation and sonoluminescence

Sonochemical (SC) processes can be increased with the application of fluid flow due to changes in bubble characteristics. In this work, a novel flow through set-up was applied to an ultrasonic horn system to investigate the effects of flow on the degradation of phenol. KI dosimetry and sonochemiluminescence (SCL) were also analysed, under the same conditions, to provide comparison of degradation to other SC processes. Further, sonoluminescence (SL) in water and different concentrations of potassium iodide (KI) and phenol solutions was studied to determine the effect of flow on processes inside the bubble that result in SL. The degradation of 0.1 mM phenol solutions, KI dosimetry and SL from phenol (0.1, 20 and 60 mM) and KI (0.1, 1 and 2 M) solutions were analysed under flow rates of 0, 24, 228 and 626 mL/min. For an ultrasonic horn system, all flow rates could augment phenol degradation beyond that of the systems without flow. At the lowest applied power, the amount of degradation was significantly increased with flow, becoming greater than degradation observed at the highest power. A strong correlation between phenol degradation and SC processes indicated that degradation followed an oxidative process. SL intensity from water, KI, and phenol solutions could also be increased with flow beyond the no flow system. For water this occurred most readily at higher powers, then for the solutes there was varied behaviour dependent upon the solute concentration. It was theorised that flow may increase the transfer of radical species to solution to enhance SC processes. An increase in SL, with flow, indicates that flow is acting to change the properties of the bubbles and/or the bubble field such that the active bubbles present collapse with greater total intensity.

Iodometric spectrophotometric determination of peroxydisulfate in hydroxylamine-involved AOPs: 15 min or 15 s for oxidative coloration?

In this study, iodometric spectrophotometry, the most-used method for detecting peroxydisulfate (PDS), was modified by increasing the concentration of potassium iodide (KI) for realizing the immediate PDS determination and avoiding the interference of hydroxylamine. Kinetic studies showed that the reaction between PDS and I− to generate the yellow-colored I3− followed the kinetic equation as -dPDSdt=dI3-dt=1.995×10-2M-2·s-1·PDS1·I-2. Detection time of the iodometric spectrophotometry was shortened from 15 min to 15 s when KI concentration was increased from 0.6 M to 4.8 M. Different with the previous iodometric spectrophotometry, the modified method using 4.8 M KI as the indicator was well tolerable to the interference of hydroxylamine at acidic pH conditions. The calibration curve of the modified method showed a well linear relationship (R2 = 0.999) between the absorbance of I3− at 352 nm and PDS concentration in the range of 0–80 μM. The modified method was highly sensitive with the absorptivity of 2.5 × 104 M−1 cm−1 and the limit of detection of 0.11 μM. Moreover, the modified method was successfully applied for monitoring the change of PDS concentration during the degradation of diclofenac with four different PDS-based AOPs, the calculated reaction stoichiometric efficiency (RSE(%)=DiclofenacdegradedPDSconsumed×100%) followed the order as heat/PDS system > hydroxylamine/Fe2+/PDS system > hydroxylamine/Cu2+/PDS system > Fe2+/PDS system.

Conductivity/Electrochemical Study of Polyvinyl pyrrolidone-Poly(vinyl alcohol)/I3\u2212 Thin Film Electrolyte for Integrated Dye-Sensitized Solar Cells and Supercapacitors

The current era focuses not only on producing solar energy but also preserving it for future use. Dye-sensitized solar cells (DSSC) and supercapacitors (SC) are such energy-based devices. DSSCs capture the solar energy and SCs store this captured energy. A natural anthocyanin dye extracted from Garcinia indica (kokum fruit) was used in the DSSCs. SnO2, one of the promising electrode materials for DSSC, was synthesized via a microwave technique. Blend polymer electrolytes (BPE) were prepared through a solution casting technique. A polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) blend with varying concentrations of potassium iodide, along with iodine dopant, was prepared as a BPE electrolyte composition. The best of the PVA-PVP/KI composition was chosen using Nyquist plots of electrochemical impedance spectroscopy (EIS). Varying the temperature, the dielectric and conductivity study of the chosen composition was studied in detail. A fast/single-step synthesis technique, namely a laser-engraved approach, was used for few-layer graphene synthesis. This graphene serves as a common platform for the DSSC-SC integrated device: as a counter electrode in DSSC and graphene-graphene symmetric electrode in SC. A DSSC-SC integrated device was fabricated and characterized using various analytical and microscopy techniques. The integrated device showed a 0.42 fill factor and 0.56% efficiency. The discharge time for integrated DSSC-SC cells was found to be increased threefold.Graphical

Cloud point extraction and FAAS determination of copper(II) at trace level in environmental samples using N-benzamido-N'-benzoylthiocarbamide and CTAB

The present work describes a simple method to detect copper(II) using flame atomic absorption spectrometry (FAAS) after pre-concentration and separation by cloud point extraction(CPE) using N-benzamido-N'-benzoylthiocarbamide (HBBTC) complexing agent and cetyltrimethylammonium bromide (CTAB) as a cationic surfactant. The different experimental parameters such as pH, the concentration of the reagent, centrifuging time, and concentration of CTAB and potassium iodide were examined to increase the extraction efficiency of the proposed procedure. Under optimized extraction conditions the limits of detection and limits of quantification were found to be 0.9 and 2.70 ng mL−1, respectively. The present work was successfully employed for the determination of copper(II) in synthetic mixtures and in water samples with a recovery% greater than 97% and RSD(%) = 0.18 %.

Simple and Easily Applicable Method for Reducing Freshwater Consumption in Dyeing of Wool Fabric

ABSTRACT Textile wet processing is one of the most water-consuming industries. The deficiency of soft water in some parts of the world urged the researchers to exert effort toward minimization of water consumption during textile wet processes. In this work, we bleach wool fabrics by hydrogen peroxide, followed by utilization of the discharged bleaching bath (DBB) in dyeing of wool with acid, reactive, and basic dyes. The residual H2O2 in the bleaching bath was decomposed into water and oxygen by adding low concentrations of potassium iodide (KI). Results of this investigation clarify that treatment of the DBB with KI is mandatory to make the bath appropriate for wool dyeing. The dyeability of wool toward the said dyes in KI-treated DBB is significantly higher than that upon dyeing with tap water. The fastness properties of the dyed fabric to washing, perspiration, and light were assessed. The turbidity, pH, total dissolved salts (TDS), total suspended salts (TSS), biological oxygen demand (BOD), and chemical oxygen demand (COD) of the bleaching effluent were assessed. Solubility of bleached/dyed wool fabrics in alkali and urea-bisulfite solutions assures the modification of some disulfide bonds along wool keratin macromolecules into cystine oxides/cysteic acid residues, and consequently the dyeability was enhanced.

Research of the influence of soybean germination on changes in the amino acid composition and the content of phytic acid

Providing the population with environmentally friendly protein products of plant origin is an important task of national importance in any country. However, the native use of soybeans today is limited due to the presence of anti-nutrients in them, namely the content of phytic acid, which can increase the formation of intestinal gas. It is possible to reduce the content of phytic acid in legumes during germination. Vegetable protein, which is the main component of legumes, has the ability to accumulate inorganic trace elements, transforming them into organic forms during soaking during germination. The object of research is «Diamond» early ripe soybean variety with a protein content of 43.88 % 2018 harvest from the Agrotek collection nursery (Kyiv, Ukraine). The characteristics of the soaking solutions are with a concentration of potassium iodide of 38 g/1000 cm3 H2O, which corresponds to theiodine content in the solutions of 41 μg/g and satisfies 1/3 % of the daily need for iodine. The grain is soaked for 48 hours. In the course of the research, the method of ion exchange chromatography, the AAA T-339m amino acid analyzer (Czech Republic) and the TM Shimadzu LC-20 chromatograph (Japan) are used. The phytic acid content is determined by the Lott method. It is established that the total amino acid content in native grain sprouted in aqueous solutions and sprouted in a solution with potassium iodide (KI) content increases from 288.8 to 443.6 and 562.6 μg/g of dry matter, respectively. The content of phytic acid is studied and it is found that its content in native grain is 29.3 g/kg, sprouted in aqueous solutions – 8.6 g/kg, sprouted in a KI solution – 3.2 g/kg. From the experiment it is possible to conclude that the process of germination of soybean grains in KI solutions affects the increase in amino acid content by almost 50 %. Due to the high hydrophilicity of the protein, the mass of germinated grains increases by 2 times. Let's assume that the solution with KI is a synergist of phytic acid inactivation. The conducted research complex is the scientific basis for the use of this raw material in the technology of meat products for people with chronic colitis and iodine deficiency conditions.

Low Environmental Impact Cleaning Technology with Ozone Micro-Bubbles Generated by a Venturi Tube

Cleaning technology is widely used to remove oil or resist from metal and semiconductor and soon. However, it causes high cost and severe environmental impacts because of the sewage disposal. Owing to strong oxidizing ability and self-decomposing power, ozone micro-bubbles generated by a Venturi tube was proposed. The purpose of this study is to research the capability of ozone micro-bubbles and improve the cleaning mechanism. In this study, we focus on the microbubble generator with a Venturi tube. We visualized the Venturi Tube by a high-speed camera to measure the bubble diameter. We also measure the shear stress near the test piece surface by using PIV. And by titration with Potassium iodide, ozonated water and ozone gas concentration are measured. Ozone gas is well dissolved after passing through the Venturi tube. Also, brass test pieces applied with cutting oil and latex resin are washed by using bubbly flow with ozone micro-bubbles. It has been confirmed that ozone micro-bubbles are able to clean the test pieces efficiently.

Redox-derivatization reaction-based rapid and sensitive determination of nitrite using resonance Rayleigh scattering method.

It remains a problem for direct detection of small inorganic nitrite ions using resonance Rayleigh scattering (RRS) method based on the direct dye-binding reaction. In the present study, a redox-derivatization reaction taking only 5min was introduced prior to nitrite detection. In the redox-derivatization reaction, nitrite ions were reduced by excess iodine ions to generate triiodide ions (I3-), which were further derivatized with a cationic dye (basic violet 1, BV1) to form the ion associates of I3--BV1. Therefore, the RRS signal was significantly enhanced, resulting from the increase of particle size and resonance-enhanced scattering effect. The analytical procedure was performed by just mixing nitrite, oxidant, acid, and dye all-in-one, avoiding the tediousness of a multi-step process or the preparation of nanoparticles. The whole detection process including the redox-derivatization reaction was less than 6min. The reaction conditions such as concentration of hydrochloric acid, potassium iodide, and BV1, reaction time, and temperature were investigated. Under optimum conditions, the concentration of nitrite was linear with an RRS signal of I3--BV1 ion associates at 320nm in the range of 0.015-1.2mg/L. The limit of detection (LOD) was calculated to be 3.0μg/L. The RRS method was applied to the determination of nitrite in real samples such as pork sausage, milk powder, and water with recovery of 95.2-112%. With advantages of rapidness, high sensitivity, and high selectivity, the method indicates potential applicability for detection of nitrite in complex samples. The method also provides an instructive protocol for detection of analytes that generate no/weak RRS enhancement after the direct dye-binding reaction. Graphical abstract.

Combined effects of flow, surface stabilisation and salt concentration in aqueous solution to control and enhance sonoluminescence.

Sonoluminescence (SL) intensity can be increased with potassium iodide (KI) concentration, attributed to a reduction in the gas concentration of solution. However, bubble properties and active bubble distributions at different frequencies and powers also influence SL intensities. Hence, to elucidate how salt concentration affects SL intensity, a systematic study with parametric variation was undertaken. SL from KI solutions of 0.1, 1 and 2 M concentration, without flow and in the presence of flow at 24, 228 and 626 mL/min was investigated at 44, 300 and 1000 kHz. At all frequencies an increase in KI concentration caused a change in the active SL distributions. For 44 kHz, localised and standing wave field SL activity could be expanded. Flow at this frequency augmented SL and SL was maximised at the lowest power setting under stabilisation at the highest KI concentration. At 300 and 1000 kHz, attenuation of the sound field was reduced, allowing expansion of activity throughout solution. In this instance, augmentation of SL intensity was only observed under flow conditions at concentrations of 1 M (300 kHz) and 2 M (1000 kHz) under stabilisation. It was theorised that a combination of smaller bubbles at higher KI concentrations and flow effects could reduce bubble clustering and enhance field formations. This was most prevalent where the standing wave was reinforced under stabilised (44 and 300 kHz) or flow (1000 kHz) conditions, here the number of active bubbles in high pressure regions likely increases. Lastly, it was found that in KI solutions flow could localise SL activity beneath and at the flow inlet via reflection and aeration mechanisms.

Production of Ozone and the Simple Detection using Potassium Iodide Titration Method

Ozone is a molecule consisting of three oxygen atoms (O3) and a powerful oxidizing agent that can also act as a non-chemical disinfectant. Ozone can be detected using potassium iodide and titrated using sodium thiosulfate to know the concentration. The purpose of this study is to know the output of ozone concentration from the ozone generator. Ozone measurement was done by making KI solutions and the concentration are 0,2; 0,4; 0,6; 0,8; and 1 M then flew by ozone for 2 minutes with flow rate 1 L/min and the color of the solution will change from clear to brown. The brown solution titrated using Na2S2O3 0,4M solution, until the color of the KI solution becomes clear again. In conclusion, potassium iodide (KI) can detect the output of ozone generator which means potassium iodide (KI) concentrations linier with ozone concentration.

Consideration of Influential Factors on Bioleaching of Gold Ore Using Iodide-Oxidizing Bacteria

Iodide-oxidizing bacteria (IOB) oxidize iodide into iodine and triiodide which can be utilized for gold dissolution. IOB can be therefore useful for gold leaching. This study examined the impact of incubation conditions such as concentration of the nutrient and iodide, initial bacterial cell number, incubation temperature, and shaking condition on the performance of the gold dissolution through the experiments incubating IOB in the culture medium containing the marine broth, potassium iodide and gold ore. The minimum necessary concentration of marine broth and potassium iodide for the complete gold dissolution were determined to be 18.7 g/L and 10.9 g/L respectively. The initial bacterial cell number had no effect on gold dissolution when it was 1 × 104 cells/mL or higher. Gold leaching with IOB should be operated under a temperature range of 30–35 °C, which was the optimal temperature range for IOB. The bacterial growth rate under shaking conditions was three times faster than that under static conditions. Shaking incubation effectively shortened the contact time compared to the static incubation. According to the pH and redox potential of the culture solution, the stable gold complex in the culture solution of this study could be designated as gold (I) diiodide.

Optical properties wheat starch iodine polysaccharides

The amylosecontents in starch is one of its qualitycharacteristics. Generally it is a specific sign of astarch-containing material and the starch received from it. Physical and chemical properties of starch and its use in the national economy depend on it. In small quantities the amylose is received by starch fractionating. It is the difficult and expensive technology. Selectors carry out research workson creation of new varieties of potatoes, grain and leguminous crops with the increased content of amylose in starch. They need techniques of definition of amylose in different types of raw materials. But before developing a technique, it is necessary to investigate optical properties of this or that type of starch and the components making it. It showed from researches, different types of starchhad differentoptical properties of itscomponents. For example, the technique developed for definition of amylose in corn starch isn't acceptable for its definition in starch of triticale and wheat. Earlier we studied properties of iodine polysaccharides of corn and triticale starches and factors affecting the optical properties of iodine polysaccharides. In this work it was investigated the influence of amylose, concentration of iodine and potassium iodide at KI:I from 3 to 15 on an optical density of wheat iodine polysaccharidessolutions. It is established that the iodine amylose of wheat has a maximum at 600 nanometers, an iodine amylopectin has at 565 nanometers. Spectra of wheatpolysaccharides differ in value of an optical density ?max and a form of curves from related polysaccharides of triticale. Concentration of an iodine in the studied solution has to be equal 0.6 mg/cm3, and a ratio of potassium iodide to an iodine has to be 5.

High-Pressure Oxidative Leaching and Iodide Leaching Followed by Selective Precipitation for Recovery of Base and Precious Metals from Waste Printed Circuit Boards Ash

: This paper deals with the recovery of gold from waste printed circuit boards (WPCBs) ash by high-pressure oxidative leaching (HPOL) pre-treatment and iodide leaching followed by reduction precipitation. Base metals present in WPCB ash were removed via HPOL using a diluted sulfuric acid solution at elevated temperatures. Effects of potassium iodide concentration, hydrogen peroxide concentration, sulfuric acid concentration, leaching temperature, and leaching time on gold extraction from pure gold chips with KI–H2O2–H2SO4 were investigated. The applicability of the optimized iodide leaching process for the extraction of gold from the leach residue obtained after HPOL were examined at different pulp densities ranging from 50 g/t to 200 g/t. Results show that the removal efficiency was 99% for Cu, 95.7% for Zn, 91% for Ni, 87.3% for Al, 82% for Co, and 70% for Fe under defined conditions. Under the optimal conditions, the percentage of gold extraction from the gold chips and the residue of WPCBs was 99% and 95%, respectively. About 99% of the gold was selectively precipitated from the pregnant leach solution by sequential precipitation with sodium hydroxide and L-ascorbic acid. Finally, more than 93% of gold recovery was achieved from WPCB ash by overall combined processes.

Characteristics of ionically conducting jatropha oil-based polyurethane acrylate gel electrolyte doped with potassium iodide

Abstract Currently, there is a growing trend of using bio-based materials from renewable resources in the construction of polymer electrolytes. In this study, a gel polymer electrolyte from Jatropha oil-based polyurethane acrylate (PUA) was prepared by doping the PUA with various concentrations (0–30 weight%) of potassium iodide (KI) salt. The PUA gel electrolyte was characterized by Fourier-transform infrared spectrometry (FTIR), thermal analysis and electrochemical analysis was performed by using electrochemical impedance spectroscopy. Subsequently, the dielectric properties of the gel polymer electrolyte were studied. A conductivity of 1.59 × 10−4 S cm−1 was achieved for the PUA incorporated with 25 weight% KI at room temperature. The dielectric study indicated the non-Debye nature of the materials. It has been shown, via transference number measurement that the conducting species in this work were predominantly ions, with only 4% contribution from electrons. An electrochemical stability window of 2.0 V was obtained by using linear sweep voltammetry for the highest conducting gel electrolyte.

Maternal marginal iodine deficiency delays cerebellar Bergmann glial cell development in rat offspring: Involvement of Notch signaling pathway

During early pregnancy, iodine deficiency (ID) is linked to adverse effects on child motor and psychomotor function. Maternal marginal ID has become a common public health problem. It is unclear whether marginal ID influences the development of the cerebellum or its underlying mechanisms. Thus, the purpose of this study was to determine the effects of marginal ID on the development of cerebellar Bergmann glial cells (BGs) and investigate the activation of the Notch signaling pathway, which is crucial for the development and morphology of BGs. We treated Wistar rats with an ID diet (iodine content 60 ± 1.5 ng/g) supplemented with deionized water containing different concentrations of potassium iodide (KI) (183, 117, and 0 μg/L for the control, marginal ID, and severe ID groups, respectively) during pregnancy and lactation. We explored the morphology of the BGs by Golgi-Cox staining and immunofluorescence and investigated the Notch signaling pathway using western blot. Our results showed that the marginal ID and severe ID groups had decreased cerebellar BG fiber lengths (P < 0.05 and 0.01, respectively) and numbers (P < 0.01 for both) on postnatal day (PN) 7, PN14, and PN21 compared to the control group. Moreover, the data showed that severe ID significantly reduced Dll1, Notch1, RBP-Jκ, and BLBP protein levels at all three time points. Marginal ID slightly reduced the expression of Notch1 on PN7 (P < 0.05) and PN21 (P < 0.01), RBP-Jκ on PN14 (P < 0.01) and PN21 (P < 0.05), and BLBP on PN7 (P < 0.05). There was no significant difference in Dll1 protein levels between the marginal ID and control groups at any time point. Our study suggests that marginal ID leads to mild damage to BG morphogenesis in the cerebellum. The abnormal regulation of the Notch signaling pathway may be involved in the damage to BGs.

Oxidative stress-mediated autophagic cell death participates in the neurotoxic effect on SH-SY5Y cells induced by excessive iodide.

Excessive iodide could induce intellectual damage in children, which has attracted broad attention. To investigate the neurotoxic effect of iodide and its mechanism, a human dopaminergic neuroblastoma cell line (SH-SY5Y) was treated with different concentrations of potassium iodide (KI). The results showed that excessive iodide could decrease cell viability, reduce glutathione (GSH) and superoxide dismutase (SOD), and increase the degree of autophagy (by changing the cellular ultrastructure and raising the autophagy-related mRNA and protein expression of LC3, Beclin1, and p62), which were correlated with the immunofluorescence labeling. Furthermore, treatment with the autophagy inhibitor 3-methyladenine (3MA), antioxidant N-acetylcysteine (NAC) and 30 mM KI for 24 h was conducted in the following research. 3MA significantly decreased autophagy-related mRNA and protein expression and improved cell viability, indicating that excess iodide induced autophagic cell death. In addition, oxidative stress regulated autophagy, reflected by the results that NAC decreased the mRNA and protein expression of LC3, Beclin1, and p62. In summary, autophagic cell death mediated by oxidative stress may participate in excessive iodide-induced SH-SY5Y cell death.

Gelatin: A green corrosion inhibitor for carbon steel in oil well acidizing environment

Corrosion inhibition performance of an environmentally benign compound, gelatin on X60 steel in 15% hydrochloric acid (HCl) at 25 °C, which simulate oil well acidizing environment was investigated in this study. The inhibition efficiency of the gelatin was examined using weight loss, potentiodynamic polarization (PDP), linear polarization (LPR), and electrochemical impedance spectroscopy (EIS) measurements techniques. Both the weight loss and the electrochemical results showed that the gelatin exhibits high inhibition efficiency and the inhibition efficiency increases with increasing gelatin concentration. The addition of low concentration of potassium iodide improves the inhibition efficiency of gelatin considerably. The ATR-FTIR and SEM/EDX surface morphology analyses provide evidence of formation of protective gelatin film on the metal surface. The gelatin molecules are predicted to adsorb on the metal surface through an interaction between the nitrogen and oxygen atoms of gelatin and the metal surface to form a metal/gelatin complex on the metal surface.

Enhanced performance of ultracapacitors using redox additive-based electrolytes

Different concentrations of potassium iodide (KI) as redox additive had been added to 1 M sulfuric acid (H2SO4) electrolyte with an aim of enhancing the capacitance and energy density of ultracapacitors via redox reactions at the interfaces of electrode–electrolyte. Ultracapacitors were fabricated using chemically treated activated carbon as electrode with H2SO4 and H2SO4–KI as an electrolyte. The electrochemical performances of fabricated supercapacitors were investigated by impedance spectroscopy, cyclic voltammetry and charge–discharge techniques. The maximum capacitance ‘C’ was observed with redox additives-based electrolyte system comprising 1 M H2SO4–0.3 M KI (1072 F g− 1), which is very much higher than conventional 1 M H2SO4 (61.3 F g− 1) aqueous electrolyte-based ultracapacitors. It corresponds to an energy density of 20.49 Wh kg− 1 at 2.1 A g− 1 for redox additive-based electrolyte, which is six times higher as compared to that of pristine electrolyte (1 M H2SO4) having energy density of only 3.36 Wh kg− 1. The temperature dependence behavior of fabricated cell was also analyzed, which shows increasing pattern in its capacitance values in a temperature range of 5–70 °C. Under cyclic stability test, redox electrolyte-based system shows almost 100% capacitance retention up to 5000 cycles and even more. For comparison, ultracapacitors based on polymer gel electrolyte polyvinyl alcohol (PVA) (10 wt%)—{H2SO4 (1 M)–KI (0.3 M)} (90 wt%) have been fabricated and characterized with the same electrode materials.

HYDRODYNAMIC CAVITATION USING DOUBLE ORIFICE- PLATES FOR THE GENERATION OF HYDROXYL RADICALS

The generation of hydroxyl radicals (OHŸ) by hydrodynamic cavitation (HC) using single and double orifice plates was studied. Five orifice plates with different configurations (size and number of orifice, total orifice area) were tested. The formation of OHŸ was measured by iodide dosimeter method using spectrophotometer at 355 nm wavelength. The effects of plate configurations and double plate arrangements on OHŸ generation were investigated in 60 minutes of reaction time using an inlet pressure of 45 psi and initial potassium iodide (KI) concentration of 20 g/L. The generation of OHŸ were expressed in terms of concentration and percentage of increase of iodine liberation. The liberated iodine for single plate ranged from 0.26 to 0.56 g/L (84 to 180% increase). The highest liberation was achieved using plate with the lowest total flow area of orifice, which had the smallest cavitation number. The double plate arrangement produced the highest iodine liberation (1.30 g/L; 420% increase) with the highest cavitational yield (2.9 x 10-1 mg/J) as compared to those of single plate arrangement. In double plate arrangement, the enhancement was dependent on the configuration and arrangement of the plates.

Development of a MSFIA system for sequential determination of antimony, arsenic and selenium using hydride generation atomic fluorescence spectrometry

This paper proposed a multisyringe flow injection analysis (MSFIA) system for antimony, arsenic and selenium determination in peanut samples by hydride generation atomic fluorescence spectrometry (HG-AFS). The optimization step of the hydride generation was performed using a two-level full factorial design involving the parameters: hydrochloric acid, sodium tetrahydroborate and potassium iodide concentrations. So, using the chemical conditions optimized, this method allows the determination of these elements employing the external calibration technique using aqueous standards with limits of detection and quantification of 0.04 and 0.14µgL−1 for antimony, 0.04 and 0.14µgL−1 for arsenic and 0.14 and 0.37µgL−1 for selenium, respectively. Additionally, the effect of vanadium, chromium, cobalt, nickel, zinc, copper, iron and molybdenum on the generation of chemical vapour was also studied. The precision expressed as relative standard deviation varied from 1.2 to 3.6% for antimony, 1.8–3.9% for arsenic and 1.8–2% for selenium. The accuracy for arsenic and selenium was confirmed using the certified peach leaves reference material SRM 1547 produced by National Institute of Standard and Technology. The proposed method showed 45 injection throughput (h−1) using 1.6mL sample volume for each element, 0.8mL NaBH4 0.5% (w/v) containing NaOH 0.05% (w/v), 0.8mL HCl 5M and 0.4mL KI 14% (w/v) containing L-ascorbic acid 2.5% (w/v). The method was applied to the determination of antimony, arsenic and selenium in peanut samples, which were firstly lyophilized and afterward digested using microwave assisted radiation. Six samples were analyzed and the contents of the elements found were: 28.7–41.3µgkg−1 for arsenic, 86.4–480.1µgkg−1 for selenium and 32.6–52.4µgkg−1 for antimony. Addition/recovery tests were also performed to confirm the method accuracy for the three elements.