Inorganic tin(II) determination by FIA with amperometric detection of its oxinate complex

A highly selective, rapid and direct amperometric method, based on the formation of a complex between tin(II) and 8-hydroxyquinoline (oxine), has been developed for the determination of trace levels of tin(II) using flow injection analysis. Tin(II) electro-oxidation was catalyzed by oxine; its oxidation peak occurred at +0.05 V vs. Ag/AgCl at a glassy carbon electrode in 0.1 mol 1(-1) acetate buffer (pH 6). A linear relationship was obtained between the peak current and the tin(II) concentration in the range 0.25-20 mumol 1(-1). The detection limit was 0.1 mumol 1(-1) and the relative standard deviation calculated by the injection of a 10 mumol 1(-1) tin(II) solution was 5% (n = 20). Optimization of several experimental parameters has been carried out and the influence of numerous cations and possible interfering molecules encountered in radiopharmaceuticals and in dental gels has been investigated. The method was applied to the determination of tin(II) in dental gels.Journal Articleinfo:eu-repo/semantics/publishe

Open digestion under reflux for the determination of total arsenic in seafood by inductively coupled plasma atomic emission spectrometry with hydride generation

A method for the determination of arsenic (As) in seafood by inductively coupled plasma atomic emission spectrometry with continuous hydride generation is described. Several analytical parameters have been investigated and optimised. The analytical features of the method (recovery, precision, accuracy and limit of detection) were calculated. Practical detection limit of 3.6mug/kg fresh weight for As has been reached. The precision of the method expressed as relative standard deviation (R.S.D.) was in the range of 2.7-3.7% and the recovery percentage ranged from 98.4 to 101.8%. The reliability of the developed method was checked by analysing several certified reference materials. A complete mineralization was obtained for arsenobetaine (AsB) containing reference material with a mixture of nitric and sulphuric acids followed by adding hydrogen peroxide in an open digestion system. This method can be applied to routine analysis without any risks of interferences</p

Comparison of four analytical techniques based on atomic spectrometry for the determination of total tin in canned foodstuffs.

&lt;p&gt;Different techniques for the determination of total tin in beverages and canned foods by atomic spectrometry were compared. The performance characteristics of inductively coupled plasma-mass spectrometry (ICP-MS), hydride generation-inductively coupled plasma-atomic emission spectrometry (HG-ICP-AES), electrothermal atomisation-atomic absorption spectrometry (ETA-AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) were determined in terms of linearity, precision, recovery, limit of detection, decision limit (CCα) and detection capability (CCβ) (Decision 2002/657/EC). Calibration ranges were covered from ng l⁻¹ to mg l⁻¹ level. Limits of detection that ranged from 0.01, 0.05, 2.0 to 200 µg l⁻¹ were reached for ICP-MS; HG-ICP-AES; ETA-AAS and ICP-AES, respectively. Precision, calculated according to ISO 5725-2 for repeatability and within-laboratory reproducibility and expressed as relative standard deviation (RSD), ranged from 1.6% to 4.9%; and recovery, based on Decision 2002/657/EC, was found to be between 95% and 110%. Procedures for the mineralisation or extraction of total tin were compared. Wet digestion, sequentially, with nitric acid and hydrogen peroxide provided the best results. The influence of possible interferences present in canned food and beverage was studied, but no interference in the determination of tin was observed. Since maximum levels for tin established by European Union legislation vary from 50 mg kg⁻¹ in canned baby foods and infant foods up to 200 mg kg⁻¹ in canned food, ICP-AES was chosen as the preferred technique for routine analysis thanks to its good precision, reliability and ease of use. The accuracy of this routine method was confirmed by participation in six proficiency test schemes with z-scores ranging from -1.9 to 0.6. Several canned foodstuffs and beverage samples from a local market were analysed with this technique.&lt;/p&gt;</p

Migration of 18 trace elements from ceramic food contact material: influence of pigment, pH, nature of acid and temperature.

&lt;p&gt;The effect of pH, nature of acid and temperature on trace element migration from ceramic ware treated with 18 commercially available glazes was studied. Besides of the well-studied lead and cadmium, migration of other toxic and non toxic elements such as aluminum, boron, barium, cobalt, chrome, copper, iron, lithium, magnesium, manganese, nickel, antimony, tin, strontium, titanium, vanadium, zinc and zirconium was investigated in order to evaluate their potential health hazards. Trace element concentrations were determined with Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). This study suggests that there is indeed a health risk concerning the possible migration of other elements than lead and cadmium. At low pH (2&lt;pH&lt;3), the nature of the acid plays an important role. Citric and malic acid seem to be more aggressive to the glaze than acetic acid except for aluminum, barium, chromium, iron and magnesium. The migration kinetics between pH 2 and 3 in acetic acid of these exceptions also are more exponential while the other elements display a decreasing linear gradient. In ceramics used for this study (fired at 900 °C), a linear relationship between the migration and the temperature was observed.&lt;/p&gt;</p

Determination of tin(II) in pharmaceuticals by amperometric oxidation after complexation with tropolone

FLWINinfo:eu-repo/semantics/publishe

Tea brewed in traditional metallic teapots as a significant source of lead, nickel and other chemical elements

An environmental inquiry conducted by the Brussels Inter-communal Laboratory of Chemistry and Bacteriology (BILCB) has revealed that in 2000 a traditional metallic teapot caused in Brussels lead intoxication among a family of Morocco origin. Following this case study of lead poisoning and subsequent preliminary results carried out by the BILCB, which confirmed the dangerousness of this kind of item, samples of traditional metallic teapots were collected from North African groceries in Brussels by the Institute of Public Health (IPH) in collaboration with the BILCB and the Federal Agency for the Safety of the Food Chain (FASFC). Aluminium, copper, iron, nickel, lead and zinc were analysed to identify metals with a potential to migrate into tea solutions. Simulants (natural tea, tea acidified with citric acid and citric acid) were brewed in those teapots in order to identify the leaching potential of migration at boiling point temperature for different contact periods. Multielementary analysis was carried out by inductively coupled plasma-atomic emission spectrometry (ICP-AES). It was concluded that the concentrations of those leached metals depend on the nature of the migration liquids, the type of teapots and the contact periods. Most teapots showed a high level of toxic metals in leachates for lead and to a less extent for nickel, which can contribute significantly to the risk of serious poisoning. A comparison of the results with the toxicological reference values was done. The teapots were withdrawn from the market by the FASFC. © 2011 Taylor & Francis.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Lead migration from ceramicware in contact with foodstuff: effect of glaze, temperature, pH and food simulant

Lead (Pb) release from non-conforming flatwares and artisanal hollowwares was measured by ICP-AES. Influence ofacidic beverages (tomato juice, vinegar and lemon juice), food simulants (acetic acid, citric acid, and malic acid) at pH (2.37-5.00),contact time (t) (30 min-2 days), temperature (T) (20 °C-90 °C), and glaze were investigated. Pb release was lowest in tomato juiceand highest in lemon juice (t = 24 h; T = 22 °C). In acetic acid 4% (v/v) Pb release was 14% less than in lemon juice. Variabilitybetween the flatwares used for experiments in lemon juice and acetic acid 4% (v/v) corresponds to 3.48% and 7.03% respectively.According to the set of experiments where three food simulants were compared, it appeared that acetic acid, citric acid, and malicacid have the same leaching capacity above pH 3, but at pH &lt; 3, citric acid appears to be the strongest extractant. Moreover, theinfluence of the applied ceramic glaze played an important role in lead release, in certain cases doubling the extracted amount of Pb.It has also been demonstrated that migration kinetics in citric acid is stronger. At 90 °C, after 2 h, the amount of extracted lead is18% more important than at 20 °C after 24 h in acetic acid 4% (v/v) which may question the capacity of consumer protection of ED84/500/EEC.</p