Rice Labeling according to Grain Quality Features Using Laser-Induced Breakdown Spectroscopy.

Rice is an important source of nutrition and energy consumed around the world. Thus, quality inspection is crucial for protecting consumers and increasing the rice's value in the productive chain. Currently, methods for rice labeling depending on grain quality features are based on image and/or visual inspection.

Characterization and predictive modeling potential of aging time of roasted coffee using infrared spectroscopy.

Repackaging and tampering with labels of foods to extend their shelf life is an illegal practice, increasingly common in some Brazilian coffee retail markets. Fast, easy-to-use, and low-cost analytical techniques for the large-scale screening of aging time have been demanded lately to fight the growth of these frauds in retail coffee markets. In this work, was evaluated as a provider of relevant regressors, chemically explainable, aiming for predictive models for estimating the aging of roasted and packaged coffees during their shelf life.

Raman spectroscopy coupled to high-resolution continuum source flame molecular absorption spectrometry for sequential determination of nitrogen species in fertilizers.

Raman spectroscopy (RS) was used to identify and quantify different nitrogen species in fertilizers. This is a fast and inexpensive method that requires no extensive sample preparation. Urea and nitrate were determined at 1000 and 1045 cm, respectively.

Simultaneous determination of phosphite and phosphate in fertilizers by Raman spectroscopy.

Raman spectroscopy is emerging and powerful technique for identifying oxyanions of phosphorus, but it still is not straightforward applied to identify and quantify simultaneously phosphite and phosphate species in solution. Herein, simultaneous determination of phosphate (PO) and phosphite (PO) in fertilizer were evaluated by Raman spectroscopy. The influence of pH on Raman spectra of species was evaluated at various solution pH values, and the results showed accurate and selective analysis for phosphate and phosphite by using pH = 10.

Silver(I) complexes of 3-methoxy-4-hydroxybenzaldehyde thiosemicarbazones and triphenylphosphine: structural, cytotoxicity, and apoptotic studies.

Novel silver(i) complexes of the type [AgCl(PPh3)2(L)] {PPh3 = triphenylphosphine; L = VTSC = 3-methoxy-4-hydroxybenzaldehyde thiosemicarbazone (1); VMTSC = 3-methoxy-4-[2-(morpholine-1-yl)ethoxy]benzaldehyde thiosemicarbazone (2); VPTSC = 3-methoxy-4-[2-(piperidine-1-yl)ethoxy]benzaldehyde thiosemicarbazone (3)} were synthesized and fully characterized by spectroscopic techniques. The molecular structures of complexes 2 and 3 were determined by single crystal X-ray diffraction. Compounds 1-3 exhibited appreciable cytotoxic activity against human tumor cells (lung A549, breast MDA-MB-231 and MCF-7) with IC50 values in 48 h of incubation ranging from 5.

Synthesis, characterization and application of a novel ion hybrid imprinted polymer to adsorb Cd(II) in different samples.

Two new ionic imprinted hybrid polymers (IIHP) and their corresponding non imprinted hybrid polymers (NIHP) were synthesized. The prepared IIHP was highly selective to Cd. To prepare the IIHP, 1-vinylimidazole (VIN) was used as the functional monomer, (3-mercaptopropyl) trimethoxysilane (MP) or (3-aminopropyl) trimethoxysilane (AMP) was used as the functional organosilane, trimethylolpropane (TRIM) was used as the crosslinking agent, AIBN was used as a radical initiator and TEOS was used as a functional precursor.

Cytotoxic and apoptotic effects of ternary silver(i) complexes bearing 2-formylpyridine thiosemicarbazones and 1,10-phenanthroline.

New silver(i) compounds containing 2-formylpyridine-N(4)-R-thiosemicarbazones and 1,10-phenanthroline (phen) were synthesized and characterized by spectroscopic techniques (IR and NMR), elemental analysis, ESI-MS and molar conductance measurements. In these complexes, both phen and thiosemicarbazone ligands are coordinated in a chelating bidentate fashion. Compounds 1-3 not only showed good in vitro antiproliferative activity against human lung (A549) and breast tumor cells (MDA-MB-231 and MCF-7), with IC50 values ranging from 1.

Laser-induced breakdown spectroscopy determination of K in biochar-based fertilizers in the presence of easily ionizable element.

Laser-induced breakdown spectroscopy is an optical emission technique quite suitable for the analysis of recalcitrant materials as it eliminates complex procedures of sample preparation. However, for some simple LIBS instrumentation the detection limits are still higher compared to those of consolidated spectroscopic techniques. The aim of the present work was to develop a method for the determination of K in new biochar-based fertilizer samples using a simple single pulse LIBS arrangement.

Multi-energy calibration applied to atomic spectrometry.

Multi-energy calibration (MEC) is a novel strategy that explores the capacity of several analytes of generating analytical signals at many different wavelengths (transition energies). Contrasting with traditional methods, which employ a fixed transition energy and different analyte concentrations to build a calibration plot, MEC uses a fixed analyte concentration and multiple transition energies for calibration. Only two calibration solutions are required in combination with the MEC method.

Effect of different precursors on generation of reference spectra for structural molecular background correction by solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry: Determination of antimony in cosmetics.

Different precursors were evaluated for the generation of reference spectra and correction of the background caused by SiO molecules in the determination of Sb in facial cosmetics by high-resolution continuum source graphite furnace atomic absorption spectrometry employing direct solid sample analysis. Zeolite and mica were the most effective precursors for background correction during Sb determination using the 217.581nm and 231.

Cobalt internal standard for Ni to assist the simultaneous determination of Mo and Ni in plant materials by high-resolution continuum source graphite furnace atomic absorption spectrometry employing direct solid sample analysis.

A new method is proposed for the simultaneous determination of Mo and Ni in plant materials by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS), employing direct solid sample analysis (DSS) and internal standardization (IS). Cobalt was used as internal standard to minimize matrix effects during Ni determinations, enabling the use of aqueous standards for calibration. Correlation coefficients for the calibration curves were typically better than 0.

Bismuth as a general internal standard for lead in atomic absorption spectrometry.

Bismuth was evaluated as internal standard for Pb determination by line source flame atomic absorption spectrometry (LS FAAS), high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) and line source graphite furnace atomic absorption spectrometry (LS GFAAS). Analysis of samples containing different matrices indicated close relationship between Pb and Bi absorbances. Correlation coefficients of calibration curves built up by plotting A(Pb)/A(Bi)versus Pb concentration were higher than 0.

Determination of lead in medicinal plants by high-resolution continuum source graphite furnace atomic absorption spectrometry using direct solid sampling.

A procedure is proposed for Pb determination in medicinal plants by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) using direct solid sampling. Among Pd(NO(3))(2), Pd/Mg(NO(3))(2), NH(4)H(2)PO(4) and the W-coated platform tested as chemical modifiers, Pd(NO(3))(2) presented the best performance. Calibration plots (10-1000 pg Pb) with regression coefficients better than 0.

Internal standardization combined with dilute-and-shoot preparation of distilled alcoholic beverages for Cu determination by high-resolution continuum source flame atomic absorption spectrometry.

Internal standardization (IS) and dilute-and-shoot preparation of distilled alcoholic beverages were evaluated for the direct determination of Cu by high-resolution continuum source flame atomic absorption spectrometry. Among Bi, In, Sn and Te evaluated as internal standards, Bi and Te furnished best results. Calibration curves were built up by plotting A(Cu)/A(Bi) and A(Cu)/A(Te)versus Cu concentration (0.

Rugged, portable tungsten coil atomic emission spectrometer.

Tungsten coil atomic emission spectrometry is an ideal technique for field applications because of its simplicity, low cost, low power requirement, and independence from cooling systems. A new, portable, compact design is reported here. The tungsten coil is extracted from an inexpensive 24 V, 250 W commercial light bulb.

Determination of total sulfur in agricultural samples by high-resolution continuum source flame molecular absorption spectrometry.

The usefulness of molecular absorption was investigated for the determination of total sulfur (S) in agricultural samples by high-resolution continuum source flame molecular absorption spectrometry. The lines for CS at 257.595, 257.

Feasibility of internal standardization in the direct and simultaneous determination of As, Cu and Pb in sugar-cane spirits by graphite furnace atomic absorption spectrometry.

Bismuth and Sb were evaluated as internal standards (IS) to minimize matrix effects on the direct and simultaneous determination of As, Cu, and Pb in cachaça by graphite furnace atomic absorption spectrometry using W-coated platform plus Pd-Mg(NO(3))(2) as modifier. For 20microL injected sample, calibration within the 0.5-10microg L(-1) As, 100-1000microg L(-1) Cu and 0.

Evaluation of lubricating oil preparation procedures for the determination of Al, Ba, Mo, Si and V by high-resolution continuum source FAAS.

Microwave-assisted acid decomposition and oil-in-water emulsification were evaluated as sample pretreatment procedures to determine Al, Ba, Mo, Si and V in lubricating oils by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Average recoveries of Al, Ba and V in oil digests (107, 103 and 101%) were close to those obtained for emulsions prepared in kerosene medium (94, 113 and 95%). Average recoveries for Mo were close to 105 and 46% for emulsions and digests, respectively.

Direct determination of phosphite in fertilizers by amperometric titration.

Amperometric titration using two Pt microelectrodes for the determination of phosphite in fertilizers based on the oxidation of analyte by iodine is proposed. The influence of pH, buffer composition, temperature, and foreign species on the end point and titration time was investigated. For titrations carried out at 70 degrees C using the pH 6.

Use of the internal standardization for difficult sampling by graphite furnace atomic absorption spectrometry.

This work shows the potentiality of As as internal standard to compensate errors from sampling of sparkling drinking water samples in the determination of selenium by graphite furnace atomic absorption spectrometry. The mixture Pd(NO(3))(2)/Mg(NO(3))(2) was used as chemical modifier. All samples and reference solutions were automatically spiked with 500mugl(-1) As and 0.

Phosphite determination in fertilizers after online sequential sample preparation in a flow injection system.

A flow injection spectrophotometric system is proposed for phosphite determination in fertilizers by the molybdenum blue method after the processing of each sample two times on-line without and with an oxidizing step. The flow system was designed to add sulfuric acid or permanganate solutions alternately into the system by simply displacing the injector-commutator from one resting position to another, allowing the determination of phosphate and total phosphate, respectively. The concentration of phosphite is obtained then by difference between the two measurents.

Determination of vanadium in human hair slurries by electrothermal atomic absorption spectrometry.

This work describes an analytical procedure for vanadium determination in human hair slurries by electrothermal AAS using longitudinal heating (LHGA) and transversal heating (THGA) graphite furnace atomizers. The samples were powdered using cryogenic grinding and the hair slurries containing 0.2% (m/v) were prepared in three different media for determination of vanadium: 0.

Tungsten permanent chemical modifier for fast estimation of Se contents in soil by graphite furnace atomic absorption spectrometry.

A tungsten carbide coating on the integrated platform of a transversely heated graphite atomizer was used as a modifier for the direct determination of Se in soil extracts by graphite furnace atomic absorption spectrometry. Diethylenetriaminepentaacetic acid (0.0050 mol L(-1)) plus ammonium hydrogencarbonate (1.

Evaluation and application of bismuth as an internal standard for the determination of lead in wines by simultaneous electrothermal atomic absorption spectrometry.

A method for the direct determination of Pb in wines by simultaneous multi-element atomic absorption spectrometry (SIMAAS) using a transversely heated graphite atomizer, Zeeman-effect background corrector and internal standardization is proposed. Bismuth was used as an internal standard and Pd(NO3)2 plus Mg(NO3)2 as chemical modifier to stabilize both the analyte and the internal standard. The implementation of two pyrolysis steps avoided any build-up of carbonaceous residues on the graphite platform.