Color approach to the analysis of white crystal cane sugar for the detection of solid impurities.

BACKGROUND: Sugar is consumed worldwide and so the quality control of sugar cane is necessary. Solid impurities are an inherent part of industrial sugar processing. Dark particles and adulteration with sand must be controlled. Sixty-four samples of white crystal cane sugar analysis in the presence of both kinds of impurities (dark particles and sand) were assessed using an affordable digital image system and a multivariate calibration strategy. RESULTS: The quality parameters for the multivariate calibration models obtained to estimate sugar content were remarkable. Color descriptors from digital images allowed identification of different levels of sugar content for the following three ranges: 0-49.99 wt%, 50.03-78.99 wt%, and 82.99-100 wt%. The multivariate model using red (R), green (G), Blue (B), and luminosity (L) color descriptors showed low standard errors of cross-validation (SECV) and validation (SEV) of 7.63 and 6.01 wt%, respectively. CONCLUSIONS: The method is affordable and reliable, and might aid quick screening in situations where access to a laboratory or instrumentation is restricted. © 2021 Society of Chemical Industry.

Biofortification quality in bananas monitored by energy-dispersive X-ray fluorescence and chemometrics.

Biofortification is a nutritional strategy used to enhance nutrients in a variety of staple foods. As bananas and plantains (Musa spp.) are considered staple food in many developing countries, monitoring zinc (Zn) content in biofortified bananas is crucial to ensure this mineral intake. Bananas were biofortified by injecting Zn sulfate heptahydrate (ZnSO4·7H2O) solutions into banana trees' pseudostem (1%, 2%, and 4%) compared with the control treatment. Zinc content was estimated using energy-dispersive X-ray fluorescence (EDXRF) and multivariate calibration using partial least squares (PLS). The impressive result is the possibility of high throughput analysis of Zn in bananas after biofortification to guarantee the quality when eaten as a central portion of the diet.

Multiway Calibration Strategies in Laser-Induced Breakdown Spectroscopy: A Proposal.

In this study, a new approach to laser-induced breakdown spectroscopy (LIBS) data modeling using multiway algorithms was investigated. Two case studies, parallel factor analysis (PARAFAC) and unfolded-partial least-squares with residual bilinearization (U-PLS/RBL) algorithms were used in (1) the determination of Al, Cu, and Fe in samples of reference material of printed circuit board (PCB) from electronic waste and (2) the determination of Ca, K, and Mg in samples of a human mineral supplement, where depth was used to obtain multidimensional data in the first case and delay-time in the second. In addition, univariate calibration was applied and compared with the multiway approaches. In all cases, the calibration data set was prepared from salts. PARAFAC showed satisfactory results in the first study, with low prediction errors and good accuracy for most samples, and the U-PLS/RBL algorithm presented the best performance for mineral supplement samples.

Determination of toxic metals in leather by wavelength dispersive X-ray fluorescence (WDXRF) and inductively coupled plasma optical emission spectrometry (ICP OES) with emphasis on chromium.

The tanning industry is one of the largest environmental polluters due to high generation waste in all production processes, but the tanning is particularly worrisome due to the use of significant amounts of chromium. Cr is an element potentially toxic to both health and the environment, depending on the concentration and the oxidation state. Cr(VI) can come in contact with human skin when using leather goods, which can cause allergies and dermatitis, besides being carcinogenic. Considering that approximately 90% of the world production of leather is performed with Cr salts, the determination of this element in leather is necessary to avoid exposure to the risks that the element can provide. The main goal of this study was the development of an alternative analytical method for the determination of Cr in leathers (ovine and bovine leather tanned with Cr and vegetable tannin) using wavelength dispersive X-ray fluorescence (WDXRF) for direct solid analysis. Besides performing analysis of the chemical composition and determination of Al, As, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Ni, Pb, Sb, Sr, Ti, and Zn in leather by inductively coupled plasma optical emission spectrometry (ICP OES). Principal component analysis (PCA) was also used in the evaluation of the WDXRF and ICP OES data sets. WDXRF calibration models for Cr presented satisfactory figures of merit and the analysis of the leathers revealed an alarming concentration of total Cr in the samples reaching 21,353 mg kg-1.

Determination of Elemental Content in Solder Mask Samples Used in Printed Circuit Boards Using Different Spectroanalytical Techniques.

Solder masks are essential materials used in the manufacture of printed circuit boards (PCB). This material protects PCBs against several types of damage and performance failure. In this study, the capabilities of laser-induced breakdown spectroscopy (LIBS) were investigated for the direct analysis of solder masks typically commercialized for homemade PCB production, and inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to obtain a chemical profile for the target analytes Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Sb, Sn, and Zn. Inductively coupled plasma-mass spectrometry (ICP-MS) was also employed for the determination of potentially toxic elements, such as As, Cd, Cr, Pb, and Hg. In addition to the qualitative information that may be useful for obtaining the spectral profile related to the raw materials present in solder masks formulations, LIBS was also applied for major elements (Al, Ba, Cu, Fe, Mg, and Zn) determination, but due to the low sensitivity, the obtained results were only semi-quantitative for Ba. Regarding Cd, Cr, Hg, and Pb, the samples analyzed were following the restriction of hazardous substances (RoHS) directive of the European Union.