Determination of total arsenic, total inorganic arsenic and inorganic arsenic species in rice and rice flour by electrothermal atomic absorption spectrometry

The determination of inorganic arsenic species in food has become very important during the last few years, since As(III) and As(V) are considered carcinogenic and found at high concentrations in food products, such as rice. The present work describes the development of three different methods for the determination of total arsenic, total inorganic arsenic, and As(III)-As(V) in rice and rice flour food products, purchased from the local market by electrothermal atomic absorption spectrometry (ETAAS). The methods were based on the use of different selective extraction procedures and the optimization of all crucial instrumental and methodological parameters. By these new preparation procedures for the determination of arsenic species, the loss and transformation of analytes during the extraction and digestion steps was prevented. For the validation of each method, precision, accuracy, and selectivity have been assessed, as performance criteria. All developed methods were accurate and precise. The calculated recoveries ranged between 92% and 105% and the (%) relative standard deviation values, under repeatability or reproducibility conditions, were lower than 15% for all different concentration levels tested. The validated methods were applied successfully for the determination of total arsenic and total inorganic arsenic in a proficiency test organized by the International Measurement Evaluation Program (IMEP-107). The methods were also applied in rice and rice flour samples purchased from the Greek market and the obtained results indicated that in almost all samples total arsenic and total inorganic arsenic were detected at ng/g levels. © 2012 Elsevier B.V

Attenuation of interference in collision/reaction cell inductively coupled plasma mass spectrometry, using helium and hydrogen as cell gases-application to multi-element analysis of mastic gum

A collision/reaction cell ICP-MS was used to develop a method for the multi-element determination of Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Nb, Mo, Ag, Cd, Sb, Cs, Ba, Hg and Pb in mastic gum. Evaluation of helium and hydrogen as cell gases took place and their ability to reduce several types of interference arising from a Si, S, P, C, Cl and F based matrix was investigated. Likewise, much polyatomic interference was attenuated efficiently by the effect of kinetic energy discrimination. Moreover, a study of stopping curve measurements was performed. Thus, measurements of the ion loss caused by collisions, reaction cross-sections given by the Langevin-Gioumousis- Stevenson model and collision cross-sections were carried out. The method was validated and the calculated recoveries for all elements (at three concentration levels) were ranged between 92.6% (Ti) and 105% (Ag) and the relative standard deviation (%RSD) of reproducibility was ranged between 1.6% (Co) and 9.9% (Ca). The limits of detection ranged between 0.11 ng g-1 (Cs) and 1.12 μg g-1 (Ca). The trueness of the method was also checked by the analysis of a standard reference material (SRM, 1573a tomato leaves). © 2014 The Royal Society of Chemistry

Development and Validation of an ETAAS Method for the Determination of Tin in Canned Tomato Paste Samples

The determination of tin in canned food became very important in the last few years since it gives information about the contamination process helping to increase canned food quality and safety. The present work describes the development of a method for the determination of tin in canned tomato paste by electrothermal atomic absorption spectrometry in order to investigate the influents of (1) the industrial sample pretreatment procedure of canned tomato paste and (2) the type of materials used in packaging, on the total concentration of tin in canned tomato paste samples. For method validation, precision (repeatability and reproducibility) and accuracy (by recovery tests) have been assessed as performance criteria. The calculated recoveries ranged between 87. 9% and 91. 9%. The calculated expanded uncertainties based on the EURACHEM/CITAC Guidelines achieved from three different concentration levels were also calculated. The obtained results indicated that the method is efficiently and properly implemented. The validated method was applied for tin concentration determination in canned tomato paste purchased from the local market. In all analyzed samples, tin concentrations levels were lower than the maximum permissible value recommended by the European Regulation. © 2011 Springer Science+Business Media, LLC

Application of zirconium-iridium permanent modifier for the simultaneous determination of lead, cadmium, arsenic, and nickel in atmospheric particulate matter by multi-element electrothermal atomic absorption spectrometry

A novel and robust method for the simultaneous determination of lead, cadmium, arsenic, and nickel in atmospheric particulate matter by multi-element electrothermal atomic absorption spectrometry was developed, using zirconium-iridium coating as permanent modifier (140 μg Zr and 4 μg Ir). After 300 atomization cycles, it was necessary to add 2 μg of Ir. Due to the varying concentrations of Pb in atmospheric particulate matter, lead was monitored at two wavelengths, at the less sensitive line of 261.4 nm for high concentration samples (>20 μg L-1) or at 283.3 nm for the low concentration samples. Matrix-matched calibration had to be performed for quantitative recoveries (96-102 %). Following this approach, the four elements were determined in atmospheric particulate matter samples from an industrial area near the city of Athens in two different time periods (cold-warm) with limits of detection of 5.5 ng m-3 for Pb at 261.4 nm and 0.29 ng m-3 at 283.3 nm, 0.019 ng m-3 for Cd, 0.14 ng m -3 for As, and 0.22 ng m-3 for Ni. Lead, Cd, and As levels were very low, whereas Ni content was at comparable levels with other areas worldwide. © 2013 Springer Science+Business Media Dordrecht

Elemental content and total antioxidant activity of Salvia fruticosa

The determination of 18 elements (V, Cr, Cu, Co, Se, Sr, Sn, Sb, Ba, Bi, Pb, Cd, As, Ni, Mn, Fe, Mg and Zn) in leaves, flowers and the infusion from Salvia fruticosa, a sage grown in Greece, is described. For this purpose, flame atomic absorption spectrometry has been used for the determination of Fe, Mg, Zn and inductively coupled plasma-mass spectrometry has been used for the determination of V, Cr, Cu, Co, Se, Sr, Sn, Sb, Ba, Bi, Pb, Cd, As, Ni, Mn using 45Sc 72Ge, 115In and 232Th as internal standards. The elemental content was found to be in the range of 0.01 (Bi)-30.8 (Mn) mg/Kg (leaves), 0.30 (Bi)-39.1 (Mn) mg/Kg (flowers), 0.003 (Sb)-20.4 (Mn) mg/Kg (infusion) for V, Cr, Cu, Co, Se, Sr, Sn, Sb, Ba, Bi, Pb, Cd, As, Ni, Mn and in the range of 0.07 (Zn)-3.21 (Mg) g/kg (leaves) for Fe, Mg and Zn. The majority of the samples were collected from six sites in the island Crete and transplanted and grown in a model farm. Chemometric techniques were used to investigate the original site classification according to their elemental content, and it was proved that the initial cultivation sites were characterized by only five elements (Sb, V, Zn, Cd and Cr). The application of factor analysis revealed significant correlation between certain elements, denoting their common sources. In addition, the total antioxidant activity of the herbal preparation was determined by measuring the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity. Microwave-assisted extraction (MAE) was used to extract total antioxidants and the effect of temperature, time and solvent in the extraction efficiency was investigated. The determination of the antioxidant activity was based on the % inhibition of the absorbance signal of the radical DPPH at 515 nm, after the addition of herbal's extract. The IC 50 values were found to be in the range of 10.6-40.1 mg/L. © 2009 Springer Science+Business Media, LLC

Human exposure to chemicals in personal care products and health implications

Human exposure to major classes of personal care products (PCPs) that include disinfectants (e.g. triclosan), fragrances (e.g. musks), insect repellents (e.g. DEET), preservatives (e.g. parabens), and UV filters (e.g. benzophenones) has been reviewed. Concentrations of these toxicants in human matrices (blood, urine, or tissues) have been compiled, alongside with relevant health implications. © Springer International Publishing Switzerland 2014

Development and Validation of a Multi-residue Method for the Determination of Pesticides in Chios Mastic Gum by QuEChERS and Liquid Chromatography–Tandem Mass Spectrometry

A simple, rapid, and sensitive method was developed for the simultaneous determination of 21 pesticides from different chemical classes (organophosphorus, triazines, carbamates, and anilinopyrimidine pesticides) in Chios mastic gum (Pistacia lentiscus L. var. Chia). Quick, easy, cheap, effective, rugged, and safe (QuEChERS) technique was used for the extraction of the target analytes; the mastic gum samples were initially extracted with acetonitrile (ACN), and then, the extracts were purified by dispersive solid-phase extraction using primary secondary amine (PSA) and C18 as sorbents. The determination of pesticides in the final extract was carried out by liquid chromatography coupled with tandem mass spectrometry with electrospray ionization (LC-ESI-MS/MS). The method was validated for linearity, accuracy, precision (repeatability and inter-laboratory reproducibility), limits of detection and quantification, and the matrix effect factor. Recoveries of the pesticides fortified at 5, 50, and 500 ng g−1 ranged from 49.7 % (quinalphos) to 127 % (pirimiphos-ethyl) and reproducibility (RSDR, n = 2 × 3) ranged from 4.4 % (propham) to 20 % (pirimiphos-methyl, propham, and triazophos). The detection limits of the method were 0.8 (mecarbam, pyrazophos) to 23 ng g−1 (parathion-ethyl). The uncertainty of the method was also calculated based on the Eurachem/Citac Guidelines, and the contribution of each independent parameter was investigated. © 2014, Springer Science+Business Media New York