Optimization of Sample Preparation of Carrot-Fruit Juice for Determination of Antimony,Arsenic, and Selenium by Hydride Generation-Inductively Coupled Plasma Optical Emission Spectrometry

Sample preparation procedures for the determination of As, Sb, and Se in carrot-fruit juice by hydride generation inductively coupled plasma optical emission spectrometry (HG-ICP OES) were examined. The applicability of a partial decomposition using aqua regia and simple dilution with a 2% (v/v) HNO₃ solution were tested and compared to a traditional treatment based on the wet digestion with a HNO₃/H₂O₂ mixture. The pre-reduction and hydride generation reaction conditions were evaluated. Under the optimal conditions, the hydrides were produced in the reaction of an acidified sample with NaBH₄ after pre-reduction with ascorbic acid [0.5% (m/v)] and KI [0.5% (m/v)] in 3 mol L^?1 HCl for total As and Sb, and boiling with HCl (6 mol L^?1) for total Se. The best results were obtained for the aqua regia procedure, resulting in limits of detection (LODs) between 1.2–2.4 ng g^?1 in the samples and recoveries from 90.9% to 109.1%. The method was successfully applied (without matrix effects) for the determination of As in dense mousse and pulp juice samples and for Sb in pulp juices. Standard solutions, processed in the same way as samples, were used for the calibration. Undecomposed matrix constituents strongly influenced Se; hence this element was determined using the method of standard addition. Concentrations of studied elements in analyzed products were at the trace level, that is, 6–32 ng g^?1, 4–10 ng g^?1, and 4–13 ng g^?1 for Se, As, and Sb, respectively.     

Investigation of electrochemical hydride generation coupled to microwave plasma torch optical emission spectrometry for the determination of arsenic: analytical figures of merit,interference studies and applications to environmentally relevant samples

A continuous flow thin layer electrolysis cell with a Pt cathode in combination with a microwave plasma torch operated with Ar as working gas was used for the optical emission spectrometric determination of As with the hydride technique. Under the optimised conditions the limit of detection (3σ) in the case of the As(I) 228.81 nm emission line was 81 ng mL^?1. Especially the influence of the transition metals Cu(II), Fe(III) and Ni(II), of the hydride forming elements Sb(III), Se(IV) and Sn(II) and of Na on the determination of As was studied. Cu(II) was found to be the strongest interferent, as in the presence of 100 µg mL^?1 of Cu(II) the signal for 3 µg mL^?1 of As was reduced to 4% of the signal without interferent. Sn(II) and Sb(III) were found to yield an increase of the signal for As. L-cysteine and KI/ascorbic acid (1 : 1) at a concentration of 2% were found effective to reduce the interferences of Cu(II), Fe(III) and Ni(II). For a solution containing 3 µg mL^?1 of As and 100 µg mL^?1 of Ni(II) it was shown that in the presence of L-cysteine or KI/ascorbic acid the signal for As was 99% and 94% of the one without interferent, whereas it was only 43% without masking reagents. The procedure could be used for the determination of As in a digested coal fly ash standard reference material (NIST SRM 1633a®) with a certified value of 145 ± 15 µg g^?1 for As. A concentration of 131 ± 15 µg g^?1 was found. Additionally, As could be determined in two process water samples from a copper refinery. It was found that the amount of As determined with ECHG-MPT-OES agrees well with the values determined by FAAS and ICP-OES at the 0.02 and 1.6 g L^?1 level, respectively.     

Simultaneous determination of inorganic arsenic,antimony, selenium and tellurium by ICP-MS in environmental waters using SPE preconcentration on modified silica

This paper deals with a simplified multi-element profiling of inorganic arsenic, antimony, selenium and tellurium in the form of ⁷⁵As, ⁸²Se, ¹²¹Sb and ¹²⁵Te by ICP-MS for amounts less than 10?µg?L^?1. Internal standards such as ⁷²Ge and ²⁰⁹Bi were successfully used for the suppression of both influence of macro elements Na⁺, K⁺, Ca²⁺, Mg²⁺ or Al³⁺, and interference of limited concentrations of heavy metal ions. Modified silica sorbents Separon? SGX C18, C8, CN, NH₂, RPS and Phenyl were tested for the preconcentration of As, Sb, Se and Te (0.25–5?µg?L^?1) in the form of ion associates with cationic surfactants from 50–250?mL sample volume. 1-etoxycarbonyl-pentadecyltrimethylammonium bromide (Septonex®, 0.005?mol?L^?1) was suitable for this purpose in the presence of 4-(2-pyridylazo) resorcinol, 2-pyrrolidinecarbodithioate and 8-hydroxyquinoline-5-sulphonic acid. The quantitative retention occurred at pH 7?±?0.2 and the mixture of acetone with ethanol in ratio 1?:?1 in the presence of 0.1?mol?L^?1 HCl was used for the quantitative elution. Organic solvents and the excess of acid were removed by evaporation prior to the determination by ICP-MS. The determination of the above trace metalloids in various kinds of water with enrichment factor till 50 times on silica Separon? SGX C18 and the above reagents were compared with the standard addition method.     

Determination of antimony(III) and (V) in natural water by cathodic stripping voltammetry with in-situ plated bismuth film electrode

A method is described for the sequential determination of Sb(III) and Sb(V) using Osteryoung square wave cathodic stripping voltammetry. It employs an in-situ plated bismuth-film on an edge-plane graphite substrate as the working electrode. Selective electro-deposition of Sb(III)/Sb(V) is accomplished by applying a potential of ?500 mV vs. Ag/AgCl, followed by reduction to stibine at a more negative potential in the stripping step. Stripping was carried out by applying a square wave waveform between ?500 and ?1400 mV to the antimony deposited. The stripping peak current at ?1150 mV is directly proportional to the concentration of Sb( III)/Sb(V). The calibration plots for Sb (III) were linear up to 12.0?µg L^?1 depending on the time of deposition. The calibration plots for Sb (V) were linear up to 7.0?µg L^?1, also depending on the time of deposition. The relative standard deviation in the determination of 0.1?µg L^?1 of Sb(III) is 4.0% (n?=?5), and the limit of detection is as low as 2 ng L^?1. In case of 0.1?µg L^?1 Sb(V), the relative standard deviation is 3.0% (n?=?5) and the detection limit also is 2 ng L^?1. The method was applied to the analysis of river and sea water samples.     

Cadmium and Lead Distribution in Marine Soil Sediments,Terrestrial Soil,Terrestrial Rock,and Atmospheric Particulate Matter around Split,Croatia

The distributions of cadmium and lead in marine sediments, surrounding soil, stones, and atmospheric particulate matter were determined at different locations in Split, Croatia. The determination of cadmium and lead was performed by flame atomic absorption spectrometry whereas atmospheric particulate matter samples were analyzed by inductively coupled plasma–optical emission spectrometry. Cadmium concentrations in the stones and soil were between 0.2 to 0.6 µg g^?1 and 0.2 to 0.9 µg g^?1. The concentration in the atmospheric particulate matter were <0.2 µg m^?2 d^?1(detection limit) to 1.4 µg m^?2 d^?1. Lead concentrations in marine sediments, stones, soil, and atmospheric particulate matter ranged from 31.2 to 144.4 µg g^?1, 9.3 to 29.4 µg g^?1, 11.3 to 66.1 µg g^?1, and 0.5 to 241.4 µg m^?2 d^?1, respectively. The relationship between determined parameters was established using principal component analysis and the results are in agreement with the assumption that anthropogenic sources play important roles for lead and cadmium distribution.     

The use of electrothermal vaporization ICP-OES for the determination of trace elements in human hair using slurry sampling and PTFE as modifier

A procedure for the determination of trace elements in human hair has been proposed by electrothermal vaporization inductively coupled plasma optical emission spectrometry (ETV-ICP-OES) with slurry sampling. Slurry was prepared by immersing human hair with conc. HNO₃ and then adding a polytetrafluoroethylene (PTFE) slurry, which was used as a chemical modifier for the improvement of vaporization characteristic of analyte. The slurry was homogenized with an ultrasonic vibrator before the measurement. The vaporization behaviour of the analytes in slurry and solution and the main influence factors for the determination were studied with the addition of PTFE systematically. Detection limits for this method varied from 0.033?µg?g^?1 (Cu) to 3.21?µg?g^?1 (Zn) with the relative standard deviations (RSDs) of 2.8–7.1%. The proposed method was successfully applied for the determination of trace elements (Cu, Mn, Cr, Fe, Zn, Cd and Pb) in human hair with minimum chemical pretreatment and aqueous calibration. The accuracy was checked by comparing the results of this method with those using pneumatic nebulization (PN) ICP-OES after a conventional acid decomposition of the same sample. In addition, the standard reference material of human hair (GBW 07601) was analysed with good agreement between the results from the proposed method and the certified values.     

Determination of Heavy Metal Content in Wild-Edible Mushroom from Jordan

The heavy metal content was investigated for six mushroom species native to Jordan. Metal (Cu, Pb, Cd, Fe, Zn, Mn, Ni, and Co) content in soil substrate and their relation to metal concentrations in mushroom and underlying soil were determined by flame and graphite furnace atomic absorption spectrometry. Mushroom species and soil were collected from different places in Jordan. The highest Cu level was 51.84 µg g^?1 for the species Lepista nuda; whereas, the lowest Cu level was found to be 18.51 µg g^?1 in Calvatia utriformis. Among the wild mushrooms, the highest Pb level was found as 4.81 µg g^?1 in Bovista plumbea, whereas the lowest Pb concentration was 2.01 µg g^?1 in Calvatia utriformis. The highest Cd level was determined as 1.9 µg g^?1 for Lepista nuda, whereas the lowest Cd level was 0.58 µg g^?1 for the species of Polyporus frondosus. The highest Zn level was 58.77 µg g^?1 for the species of Lepista nuda and the lowest Zn concentration was found 35.98 µg g^?1 in Calvatia utriformis. The highest Fe level was found as 317 µg g^?1 in Lepista nuda, whereas the lowest Fe concentration was 211.7 µg g^?1 in Calvatia utriformis. The highest Mn content was 36.55 µg g^?1 for Russula delica, whereas the lowest Mn level was 24.5 µg g^?1 for the species Bovista plumbea. The highest Ni content was found as 12.65 µg g^?1 for Russula delica, whereas the lowest Ni level was 0.17 µg g^?1 for Bovista plumbea. The highest Co content in the tested mushrooms was found as 3.5 µg g^?1 for the species of Agaricus bisporus, whereas the lowest Co level was 0.85 µg g^?1 for Polyporus frondosus. The results indicated that, in general, heavy metal contents in all mushroom species were lower than the underlying soil substrates except for some mushroom species.     

Simultaneous Detection of Copper,Lead and Zinc on Tin Film/Gold Nanoparticles/Gold Microelectrode by Square Wave Stripping Voltammetry

In this work, three heavy metals (Cu(II), Pb(II) and Zn(II)) in wide potential window were simultaneously detected on tin film/gold nanoparticles/gold microelectrode (Sn/GNPs/gold microelectrode) by the method of square wave stripping voltammetry. The Sn/GNPs/gold microelectrode was fabricated by in situ plating of a Sn film on a gold nanoparticles (GNPs) modified gold microelectrode. The influence of hydrogen overflow on stripping of Zn(II) on the gold microelectrode was reduced by modification of GNPs, which made the stripping potential of target metals shift positively. The interference of sulfhydryl groups was reduced and the selectivity of the microelectrode was improved due to the addition of Sn in the detection solution. After accumulation at ?1.4 V for 300 s in acetate buffer solution (0.1 mol L^?1, pH 4.5), the Sn/GNPs/gold microelectrode revealed a good linear behavior in the examined concentration ranges from 5 to 500 µg L^?1 for Cu(II) and Pb(II), and from 10 to 500 µg L^?1 for Zn(II), with a limit of detection of 2 µg L^?1 for Cu(II), 3 µg L^?1 for Pb(II) and 5 µg L^?1 for Zn(II) (S/N=3). When compared with a Sb/GNPs/gold microelectrode and a Bi/GNPs/gold microelectrode, the Sn/GNPs/gold microelectrode showed the best stripping performance to Cu(II), Pb(II) and Zn(II). As a new type of environment‐friendly electrode, the Sn/GNPs/gold microelectrode has potential applications for detection of heavy metals.     

Determination of elements in different parts of goat brain using k 0 instrumental neutron activation analysis

Researcher’s interest is increasing worldwide to study the role of trace elements in brain tissues. This paper discusses the application of k ₀-instrumental neutron activation analysis to study the distribution of trace elements in seven different anatomical regions of goat brain. These regions include cerebellum, cerebrum, medulla oblongata, meninges, midbrain, pons and thalamus. The analysis protocol followed 1 h irradiation at 10 MW material testing type nuclear research reactor with nominal thermal neutron flux of 2 × 10¹³ cm^?2 s^?1. A total of 14 elements, namely Br, Co, Cr, Eu, Fe, Hg, K, Na, Rb, Sb, Sc, Se, Tb and Zn were determined in all parts. Reliability of the method was assessed by analyzing biological reference material IAEA-336 (lichen). On comparing the analytical results with the healthy human brain data, it showed that eight elements (Eu, K, Na, Rb, Sb, Sc, Se, Tb) were found with relatively higher elemental concentrations in human brain. Principal component analysis revealed distribution of seven parts in different three groups having similar elemental concentrations of elements.     

Trace Determination of Manganese in Urine by Graphite Furnace Atomic Absorption Spectrometry and Inductively Coupled Plasma–Mass Spectrometry

This paper describes a simple and sensitive method for the determination of manganese in human urine by graphite furnace atomic absorption spectroscopy (GFAAS), which includes sample preparation by microwave digestion. Matrix modifier combinations, the digestion power, pyrolysis, and atomization temperatures were optimized. A mixture of 5.0 µg Pd(NO₃)₂ and 3.2 µg Mg(NO₃)₂ modifier presented the best performance. The optimal temperatures for pyrolysis and atomization were 1500°C and 1950°C, respectively. The GFAAS method was compared to inductively coupled plasma–mass spectrometry (ICP–MS) for the determination of manganese in urine. Analytical figures of merit for GFAAS and ICP–MS were: accuracy (3.46%, 2.19%), precision (3.61%, 5.84%), LOD (0.109 µg · L^?1, 0.015 µg · L^?1), LOQ (0.327 µg · L^?1, 0.045 µg · L^?1), and recovery (80–100%, 74–89%). Both methods were employed for the determination of Mn in urine and the results were compared statistically.     

Simultaneous determination of hydride forming elements (As, Sb, Se, Sn) and Hg in sonicate slurries of biological and environmental reference materials by hydride generation microwave induced plasma optical emission spectrometry (SS-HG-MIP-OES)

A slurry sampling hydride generation (SS-HG) method for the simultaneous determination of hydride forming elements (As, Sb, Se, Sn) and Hg, without total sample digestion, has been developed using batch mode generation system coupled with microwave induced plasma optical emission spectrometry (MIP-OES) from certified biological and environmental reference materials. Slurry concentration up to 3.6% m/v (particles < 80 μm) prepared in 10% HCl containing 100 μl of decanol, by the application of ultrasonic agitation, was used with calibration by the standard addition technique. Harsh conditions were used in the slurry preparation in order to reduce the hydride forming elements to their lower oxidation states, As(III), Sb(III), Se(IV) and Sn(II) and Hg, being reduced to mercury vapor, before reacting with sodium tetrahydroborate. An ultrasonic probe was used to homogenize the slurry in the quartz cup just before its introduction into the reaction vessel. For 10 ml of slurry sample, detection limits (LOD, 3σ_blank, peak area) of 0.06, 0.08, 0.15, 0.12 and 0.10 μg g^− 1 were obtained for As, Sb, Se, Sn and Hg, respectively. The method offers relatively good precision (RSD ranged from 9 to 12%) for slurry analysis. To test the accuracy, three certified reference materials were analyzed with the analyte concentrations mostly in the μg g^− 1 level. Measured concentrations are in satisfactory agreement with certified values for the biological reference materials: NRCC LUTS-1 (lobster hepatopancreas), NRCC DOLT-2 (Dogfish Liver) and environmental reference material: NRCC PACS-1 (Marine Sediment), all adequate for slurry sampling. The method requires small amounts of reagents and reduces contamination and losses.     

Ion Chromatographic Determination of Traces of Sodium,Magnesium and Chlorine in Gadolinium Nitrate

Abstract

Two independent and sensitive ion chromatographic methods with suppressed conductivity were developed for determination of traces of Cl, Na, and Mg in gadolinium-nitrate. Na-Mg was determined by cation-exchange column after matrix separation, whereas Cl was analyzed without matrix separation by high capacity anion-exchange column. Detection limit for Cl was 0.01 µg mL^?1 in sample solution and 1 µg g^?1 in solid sample. The reproducibility (100 µL injected) was better than 3%, 3% and 4% at 50, 25 and 50 µg L^?1 level for Cl, Na, and Mg respectively. The overall precision was better than ±7% for Na-Mg and ±5% for Cl.     

Preconcentration of ultra-trace amounts of iron and antimony using ion pair solid phase extraction with modified multi-walled carbon nanotubes

Ion pair solid phase extraction was applied to the simultaneous preconcentration of iron and antimony. The ion pairs consisting of FeCl₄ ^? or SbCl₄ ^? anions and the benzyldimethyltetradecyl ammonium cation were formed on the surface of multi-walled carbon nanotubes, then eluted with nitric acid, and the elements finally quantified by ETAAS. The adsorption capacities of the impregnated MWCNTs are 9.2 mg g^?1 for iron and 27.5 mg g^?1 for antimony. The following analytical figures of merit were determined for iron and antimony, respectively: Enrichment factors of 210 and 230, assay precisions of ±5.3 % and ±4.8 %, linear calibration plots from 0.7 to 9.4 and 13.0 to 190 ng L^?1, and detection limits of 0.17 and 3.5 ng L^?1. The method was applied to the determination of iron and antimony in human hair, synthetic sample, and to the certified reference materials gold ore (MA-1b) and trace elements in water (SRM 1643d).

Determination of Rare Earth Elements in Navel Oranges from Different Geographical Regions of China by Inductively Coupled Plasma-Mass Spectrometry

There are three major production bases of navel oranges in China, including Southern Jiangxi Province, Southern Hunan Province, and the Three Gorges District of the Yangtze River. Southern Jiangxi and Southern Hunan are also famous for rare earth elements that are ionic, making them easily passed from soil to plants and fruits. To test the relative enrichment of rare earth elements in navel oranges from these production sites, ICP-MS analysis was performed following a microwave digestion procedure. The concentrations of La, Ce, Pr, and Nd in navel orange peels from Southern Jiangxi and Southern Hunan (1.26–1.86 µg g^?1) were much higher than results from the Three Gorges (0.23–0.46 µg g^?1). Moreover, yttrium is relatively enriched (0.25–0.29 µg g^?1) in navel orange peels from Southern Jiangxi at concentrations almost twice that from Southern Hunan (0.15 µg g^?1). The various concentrations and distribution of rare earth elements offers the possibility of traceability and authentication of navel oranges. Meanwhile, navel orange peels from Southern Jiangxi posed no risk in consumption, based on the maximum limit level (≤0.7 µg g^?1, wet weight) of rare earth elements in food issued in China (GB 2762-2005).     

Determination of Arsenic,Mercury and Barium in Herbarium Mount Paper Using Dynamic Ultrasound-Assisted Extraction Prior to Atomic Fluorescence and Absorption Spectrometry

A dynamic ultrasound-assisted extraction method using Atomic Absorption and Atomic Fluorescence spectrometers as detectors was developed to analyze mercury, arsenic, and barium from herbarium mount paper originating from the herbarium collection of the National Museum of Wales. The variables influencing extraction were optimized by a multivariate approach. The optimal conditions were found to be 1% HNO₃ extractant solution used at a flow rate of 1 mL min^?1. The duty cycle and amplitude of the ultrasonic probe was found to be 50% in both cases with an ultrasound power of 400 W. The optimal distance between the probe and the top face of the extraction chamber was found to be 0 cm. Under these conditions the time required for complete extraction of the three analytes was 25 min. Cold vapor and hydride generation coupled to atomic fluorescence spectrometry was utilized to determine mercury and arsenic, respectively. The chemical and instrumental conditions were optimized to provide detection limits of 0.01 ng g^?1 and 1.25 ng g^?1 for mercury and arsenic, respectively. Barium was determined by graphite-furnace atomic absorption spectrometry, with a detection limit of 25 ng g^?1. By using 0.5 g of sample, the concentrations of the target analytes varied for the different types of paper and ranged between 0.4–2.55 µg g^?1 for Ba, 0.035–10.47 µg g^?1 for As, and 0.0046–2.37 µg g^?1 for Hg.     

Systematic investigations of the multi-element preconcentration from copper by precipitation of the matrix as copper(I) oxide and copper(I) thiocyanate

Two methods for multi-element preconcentration from copper by reductive matrix precipitation are presented. In systematic investigations on the coprecipitation behaviour of Ag, Al, Au, Bi, Cd, Co, Cr, Fe, Ga, In, Mn, Mo, NJ, Pb, Sb, Se, Sn, Te and Zn during precipitation of the copper matrix as Cu₂O or CuSCN, the separation parameters were optimized. By combination with a hexamethyleneammonium hexamethylenedithiocarbamate collector precipitation, a concentration of 8 elements (Cu₂O precipitation) or 13 elements (CuSCN precipitation) in a small volume was achieved. The limits of detection of the procedures are, depending on the element, 0.1–5 μg g^?1 for flame atomic absorption spectrometry (AAS) and 0.01–0.1 μg g^?1 for graphite furnace AAS. The relative standard deviations are about 3%. The analytical performance of the procedures is compared with that of an electrolytic copper separation.     

Determination of reference interval values for inorganic elements in whole blood samples of humans and laboratory animals by X-ray fluorescence spectrometry

Inorganic elements are responsible for essential bodily functions, such as osmotic regulation, cardiac frequency and contractibility, blood clotting and neuromuscular excitability. The determination of inorganic elements in corporeal fluids such as blood, serum, plasma and urine is used as a monitor for a part or the whole organism; their values, then, are compared with reference interval values. In this study, the energy dispersive X-ray fluorescence spectrometry (EDXRF), applying the Fundamental Parameters method, for the determination of inorganic elements in whole blood samples from humans and laboratory animals, was used. Peripheral blood samples were collected and, before coagulation, 100 μL of sample were deposited onto Whatman No. 41 filter paper and dried, using infrared spotlight. The reference interval values for healthy Brazilian population of Na were found to be 1,788–1,826 μg g^?1, of Mg 63–75 μg g^?1, of P 602–676 μg g^?1, of S 1,519–1,718 μg g^?1, of Cl 2,743–2,867 μg g^?1, of K 1,508–1,630 μg g^?1, of Ca 214–228 μg g^?1, of Fe 170–184 μg g^?1, of Cu 4–6 μg g^?1 and of Zn 1–3 μg g^?1. The reference interval values for golden hamster (Mesocricetus auratus) of Na were found to be 1,714–1,819 μg g^?1, Mg 51–79 μg g^?1, P 970–1,080 μg g^?1, S 1,231–1,739 μg g^?1, Cl 2,775–2,865 μg g^?1, of K 1,968–2,248 μg g^?1, of Ca 209–257 μg g^?1, of Fe 145–267 μg g^?1, of Cu 4–6 μg g^?1 and of Zn 3–5 μg g^?1. A comparative study between EDXRF and instrumental neutron activation analysis data was carried out and the results for both techniques are statistically equal (α = 0.05). The results contribute for the establishment of reference interval values for Na, Mg, P, S, Cl, K, Ca, Cu and Zn in the healthy Brazilian population and the referred laboratory animal species.     

Determination of As, Ge, Hg, Pb, Sb, Se and Sn in coal slurries by CVG-ETV-ICP-MS using external or isotopic dilution calibration

A method for the multi-elemental determination of As, Ge, Hg, Pb, Sb, Se and Sn in coal reference materials by slurry sampling chemical vapor generation (CVG) using external calibration and isotopic dilution (ID) calibration and detection by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) is proposed. As, Ge, Sb, Se and Sn were determined using the external calibration, while, Hg, Pb, Se and Sn were determined by isotopic dilution. About 50–250 mg of sample was mixed with an acid solution, containing aqua regia and HCl, in an ultrasonic bath. For the isotopic dilution calibration, the enriched isotopes ²⁰¹Hg, ²⁰⁶Pb, ⁷⁷Se and ¹¹⁹Sn were added to the slurry in an adequate amount in order to produce an altered isotopic ratio close to 1. The vapor produced by the reaction of the sample slurry with the reducing agent was transported to the vaporizer and trapped in a Ir-treated graphite tube at 200 °C, before vaporization at 2100 °C and transportation of the vapor to the plasma. The accuracy of the method was assured by the analysis of four certified reference coal samples, using external calibration with aqueous solutions, prepared in the same medium and subjected to the same CVG and trapping procedure as the slurries and also by isotopic dilution calibration. The obtained concentrations were in agreement with the certified values, using the t-Student test for a confidence level of 95%. The detection limits (3 s; n = 5) of isotopic dilution, in ng g^− 1, were: 0.4 for Hg, 900 for Pb, 0.3 for Se and 0.2 for Sn. For external calibration, the detection limits, in ng g^− 1, were: 1.6 for As, 0.1 for Ge, 0.3 for Sb, 0.9 for Se and 7.5 for Sn. The relative standard deviations generally were lower than 14%, adequate for slurry analysis.     

Use of ionic liquid based chitosan as sorbent for preconcentration of fluoroquinolones in milk,egg, fish,bovine, and chicken meat samples by solid phase extraction prior to HPLC determination

The possibility of using ionic liquid based chitosan sorbent for the separation and preconcentration of fluoroquinolone antibiotics (marbofloxacin, enoxacin, ofloxacin, ciprofloxacin, and enrofloxacin) has been studied. For this reason, different ionic liquids were prepared and coated on the chitosan sorbent. The conditions of the preconcentration of fluoroquinolones on a microcolumn have been optimized and the extraction efficiencies of the prepared sorbents have been compared. The compounds were eluted with 5 mL of 20% NH₃ (v/v, MeOH) solution and determined by HPLC with diode array and fluorescence detector. The limits of detection were found as 4.23 µ g L^?1 for marbofloxacin, and 1.09 µg L^?1 for enoxacin; 3.23 × 10^?3 µg L^?1 for ofloxacin; 8.39 × 10^?3 µg L^?1 for ciprofloxacin; and 19.50 × 10^?3 µg L^?1 for enrofloxacin. The developed method was applied for the analysis of fluoroquinolone in milk, egg, fish, bovine, and chicken samples and the recoveries were obtained in the range 70–100%.     

Profiling bioactive flavonoids and carotenoids in select south Indian spices and nuts

Abstract

The objective of this study was to examine the bioactive flavonoids and carotenoids concentration in fifteen south Indian spice and two tree nut species using high performance liquid chromatography (HPLC). Among four flavonoids, catechin concentration was the highest in all spices and nuts and ranged between 97.1 and 1745.4 µg g^?1. Quercetin concentration was the greatest in cinnamon, followed by garlic and cumin and ranged from 0.4 to 65 µg g^?1 in other spices and nuts. Lutein concentration ranged from 0.1 to 102.8 µg g^?1. Of the spices and nuts studied, β-carotene concentration was highest in coriander leaves (74.7 µg g^?1), followed by red pepper (12.5 µg g^?1) and curry leaves (8.5 µg g^?1). This research shows that consumption of south Indian spices and nuts could substantially benefit consumers living in regions experiencing Vitamin A and other micronutrient deficiencies.