Method development for the determination of lead in wine using electrothermal atomic absorption spectrometry comparing platform and filter furnace atomizers and different chemical modifiers (original) (raw)
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On the determination of lead in wine by electrothermal atomic absorption spectrometry
Central European Journal of Chemistry, 2007
The parameters of analytical procedures developed for direct ETAAS determination of Pb in wine are discussed. Atomic absorption spectrometers based on transversal and longitudinal Zeeman effect, wall and integrated platform atomization with two main approaches: (i) measurements in the presence of modifier and (ii) measurements without using any modifier are compared. The optimal temperature programs are defined according to the pre-treatment and atomization curves constructed in the presence of different types of wines. For all investigated instrumental systems, 1:1 dilution of wine sample with 0.2 mol L −1 HNO 3 is recommended. Matrix interferences observed, call for standard addition calibration method for Pb quantification in wines. The detection limit (3σ) achieved for wine diluted in the ratio of 1:1 varied from 0.8 to 1.9 μg L −1 depending on the instrument used. The relative standard deviation for the concentration range of 10 to 80 μg L −1 Pb in wine is typically between 4-8%. The accuracy of the analytical procedures recommended was confirmed by comparing the results obtained with those found for wine samples previously digested with HNO 3 -H 2 O 2 mixture, by added/found method and by parallel analysis using different instruments. A total of 66 wine samples from different regions of Macedonia were analyzed.
Talanta, 2019
This paper proposes a closed inline system for decomposition of wine, aiming at the determination of lead using electrothermal atomization atomic absorption spectrometry (ETAAS). The system is built using a 0.8 mm diameter PTFE tube, which is wrapped around an 8 W UV lamp. The sample in the presence of 70% hydrogen peroxide is circulated on an 8 W UV lamp at the flow rate of 1 mL min for 45 min. Under these conditions, the carbon content varied from 10% to 2% for a red wine sample before and after digestion, respectively. The system has allowed the determination of lead in wine samples using the analytical line 283.306 nm in the presence of aluminum as the chemical modifier and pyrolysis and atomization temperatures of 800 and 1800 °C, respectively. Then, lead can be quantified employing the external calibration technique with limits of detection 0.27 and quantification 0.89 µg L, and characteristics mass of 18 pg. The precision expressed by relative standard deviation (RSD%) was 2....
Talanta, 2008
A multi-element graphite furnace atomic absorption spectrometry (GFAAS) method was elaborated for the simultaneous determination of As, Cd, Cu, and Pb in wine samples of various sugar contents using the transversally heated graphite atomizer (THGA) with end-capped tubes and integrated graphite platforms (IGPs). For comparative GFAAS analyses, direct injection (i.e., dispensing the sample onto the IGP) and digestion-based (i.e., adding oxidizing agents, such as HNO 3 and/or H 2 O 2 to the sample solutions) methods were optimized with the application of chemical modifiers.
In this study, electrothermal atomic absorption spectrometry (ETAAS) was used for determination of lead and cadmium in Macedonian white wines. Wine samples, without prior purification, were directly injected into the ETAAS system, using matrix modifiers for Pb and Cd. The standard addition method was used for quantitative analysis of Pb and Cd content. Reliability of the method was verified by determination of selected validation characteristics. The results of the measurements indicated satisfactory precision and accuracy, confirming that the method is accurate and convenient for quantitative analysis. The lead and cadmium concentrations were ranged between 2–28.5 and 0.4–5.69 μg/L, respectively. The levels were below the maximal allowed concentration in wine and compare well with those reported for similar wines from other parts of the world.
Journal of Hazardous Materials, 2009
A method for direct determination of lead in wine and rum samples was developed, using a flow injection hydride generation system coupled to an atomic absorption spectrometer with flame-quartz atomizer (FI-HG-AAS). Lead hyride (PbH 4) was generated using potassium ferricyanide (K 3 Fe(CN) 6), as oxidant and sodium tetrahydroborate (NaBH 4) as reductant. Samples were acidified to 0.40% (v/v) HCl for wine and to 0.30% (v/v) HCl for rum, which were then mixed on-line with 3% (m/v) K 3 Fe(CN) 6 solution in 0.03% (v/v) HCl prior to reaction with 0.2% (m/v) alkaline NaBH 4 solution. Lead contents of a rum and two different red wine samples were determined by FI-HG-AAS agreed with those obtained by ICP-MS. The analytical figures of merit of method developed were determined. The calibration curve was linear up to 8.0 gL −1 Pb with a regression coefficient of 0.998. The relative error was lower than 4.58%. The relative standard deviation (n = 7) was better than 12%. A detection limit of 0.16 gL −1 was achieved for a sample volume of 170 L.
Analytica Chimica Acta, 2003
Two manifold designs were evaluated. Water samples and wine digests in 10% nitric acid were pumped through a column containing a commercially available resin (Pb-Spec ®), an immobilized crown ether with a cavity size selective for Pb 2+. The column was rinsed with 2% HNO 3 and the eluent, 0.1 mol l −1 ammonium oxalate was injected via a six-port rotary valve. The eluted lead was delivered to the flame atomic absorption spectrometer at 4.0 ml min −1. The following flow-injection (FI) parameters were optimized: sample acidity and volume, loading and elution flow rates, and eluent composition and volume. The detection limit for the water samples, estimated from the noise on the signal obtained for 250 ml of 10 gl −1 loaded at 19.1 ml min −1 was 1 gl −1. For 50 ml of wine digest loaded at 4 ml min −1 , the value was 3 gl −1. The roles of loading flow rate and sample volume were investigated in detail. The variation in retention efficiency with loading flow rate showed that the amount of lead retained (during a fixed loading time) increased with flow rate until the upper performance limit of the peristaltic pump was reached. The variation of detection limit with sample volume followed the expected hyperbolic relationship and showed that only small improvements in LOD were obtained for volumes greater than 50 ml. The method was evaluated through spike recovery for both water and wine. The lead contents of tap (0.24 gl −1), pond (0.40 gl −1), and river waters (not detected) were determined. The concentrations of lead in three Port wine samples ranged from not detected to 190 gl −1. No significant matrix suppression effects were observed.
Atomic absorption spectrometry in wine analysis–a review
2009
This article reviews methods for the determination and identification of trace elements in wine by using atomic absorption spectrometry (AAS). Wine is one of the most widely consumed beverages and strict analytical control of trace elements content is required during the whole process of wine production from grape to the final product. Levels of trace elements in wine are important from both points of view: organoleptic -Fe, Cu, Mn and Zn concentrations are directly related to the destabilization and oxidative evolution of wines, and toxicological -toxic elements content should be under the allowable limit, wine identification. The identification of metals in wine is subject of increasing interest since complexation may reduce their toxicity and bioavailability. AAS is one of widely used methods for routine analytical control of wine quality recommended by the International Organization of Vine and Wine. Two main approaches -preliminary sample digestion and direct instrumental measurement combined with AAS for trace element determination in wines are reviewed and discussed. Procedures for various sample pretreatments, for trace element separation and preconcentration are presented. Advances in metal identification studies in wines based on AAS are presented.
Mikrochimica Acta, 2004
An accurate, simple and precise method for total mercury determination in wines is described. Liquid/liquid extraction of inorganic and organic mercury species directly from untreated wine samples is recommended as a preconcentration procedure prior to determination by electrothermal atomic absorption spectrometry (ETAAS). Ammonium pyrrolidinedithiocarbamate was used as complexation agent. The optimal instrumental parameters for ETAAS measurement of mercury species extracted are proposed. The detection limit for total mercury determination is 0.2 µg L−1. The relative standard deviation is 15–22% for mercury in wine in the range of 0.2–5 µg L−1. The proposed procedure has been successfully applied to the determination of mercury in bottled wines in Bulgaria and Macedonia.
Journal of Aoac International, 2001
An on-line lead preconcentration and determination system implemented with inductively coupled plasma-atomic emission spectrometry (ICP-AES) with ultrasonic nebulization (USN) in association with flow injection was studied. For the preconcentration of lead, a Pb-quinolin-8-ol complex was formed on-line at pH 6.8 and retained on Amberlite XAD-16 resin. The lead was removed from the microcolumn by countercurrent elution with nitric acid. A total enhancement factor of 225 was obtained with respect to ICP-AES with pneumatic nebulization (15.0 for USN and 15.0 for the column). The detection limit for Pb for the preconcentration of a 10 mL wine sample was 0.15 mg/L. The precision for 10 replicate determinations at a Pb level of 25 mg/L was a relative standard deviation of 2.5%, calculated from the peak heights obtained. The calibration graph obtained by using the preconcentration system for lead was linear with a correlation coefficient of 0.9995 for levels near the detection limit up to ³ 1000 mg/L. The method was successfully applied to the determination of lead in wine samples.
Determination of metals in wine with atomic spectroscopy (flame-AAS, GF-AAS and ICP-AES); a review
Food Additives and Contaminants, 2002
Metals in wine occur at the mg l 1 level or less and, though not directly related to the taste of the ®nal product, their content should be determined because excess is undesirable , and in some cases prohibited, due to potential toxicity. Lead content in wine, for example, is restricted in several states by legislation to guarantee consumer health protection. Of several methods for metal determination, techniques of atomic spectroscopy are the most sensitive and rapid. Most of the elements present in wine can be determined with these techniques, at concentrations ranging from the mg l 1 to the ·g l 1 level. Here, inductively coupled plasma-atomic emission spectrometry (ICP-AES),¯ame atomic absorption spectrometry (¯ame-AAS) and graphite furnace-atomic absorption spectrometry (GF-AAS) are compared for their characteristics as employed in metal determination in wine.