Sunflower oil has several properties that are valuable to the human skin and health; however, they are target of adulterations. In this study, in order to evaluate the authenticity of edible and cosmetics based on sunflower oils, the triacylglycerol (TAG) profiles using direct infusion electrospray ionization mass spectrometry (ESI-MS), the fatty acid (FA) composition by gas chromatography with flame ionization detection (GC-FID) and principal component analysis, of seven commercial samples were determined and the results obtained were compared with the pure sunflower and soybean oils. Of the seven brands analyzed, just one sample presented only sunflower oil in its composition; two stated in the label soybean addition; and four did not present the real composition of the product in the label. Therefore, GC-FID and ESI-MS analysis in conjunction with principal component analysis (PCA) demonstrated that they are complementary techniques and could be applied in food industries to assess the quality of vegetable oils, since results showed the need for stricter quality control for this product.

Human milk (HM) lipids provide about 50% energy and facilitate the transport and absorption of fat-soluble vitamins for infants, but their composition should be studied when the milk is processed. This study evaluated the lipid quality of lyophilized and vacuum-packed colostrum (C), transitional (T), and mature (M) HM for a period of 1, 30, 60, 90, 120, 150, and 180 days of storage at –18 ºC. From the acidity (ºDornic), lipid content, and fatty acid (FA) composition results, no significant differences in the analyzed period were observed. The relative percentage of major triacylglycerols (TAG) of the HM was not altered, showing that the lyophilization process in HM is a good alternative that could be applied in human milk banks (HMB), increasing HM preservation and facilitating its transport and storage.

Coconut oil has several domestic uses and health benefits, which can be used in food, pharmaceuticals and cosmetics products. However, it has been the target of adulteration with lower price oils and fats, such as soybean oil. In this study, a fast, easy and simple methodology was used to detect low quantities of intentionally adulterated coconut oil with soybean oil by direct infusion electrospray ionization mass spectrometry (ESI-MS) at different levels (0, 2, 5, 10, 15, 20, 30, 50, 70 and 100%). In the oil industry, intentional adulterations usually occur with the addition of low quantities of soybean oil to coconut oil. Therefore, the suggested ESI-MS method is promising for routine analysis to guarantee the quality control of coconut oil since it is possible to detect adulteration with a minimal of 2% soybean oil addition.

This study provides a fast, accurate and reproducible method for L-ascorbic acid (L-AA) determination in milk samples by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). A small volume of a low toxicity organic solvent (ethanol) was used for degreasing and deproteinization steps. Ethylenediaminetetraacetic acid disodium salt (EDTA) and formic acid were used as stabilizing agents. The method was successfully validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and inter/intra-day precision and applied in raw and processed milk samples. Good linearity (r2 > 0.9915) and low LOD and LOQ, 1.5 and 5.0 µg L-1, respectively, were obtained. The recoveries for 500 and 1000 µg L-1 spikes were higher than 90% and the precision values expressed in terms of relative standard deviation (RSD) were ≤ 6.8%. For the first time, the determination of L-AA in a 500 µg L-1 concentration range was reported for milk samples.

A new online solid phase preconcentration method using the new SiO2/Al2O3/SnO2 ternary oxide (designated as SiAlSn) as chelating agent free-solid phase extractor (CAF-SPE) coupled to flame atomic absorption spectrometry (FAAS) for Pb2+ determination at trace levels in different kind of samples is proposed. The solid adsorbent has been characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron miscroscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray fluorescence spectroscopy (XRF) and textural data. The method involves the preconcentration using time-based sampling of Pb2+ solution at pH 4.3 through 100.0 mg of packed adsorbed into a mini-column under flow rate of 4.0 mL min-1 during 5 min. The elution step was accomplished by using 1.0 mol L-1 HCl. A wide range of analytical curve (5.0-400.0 µg L-1), high enrichment factor (40.5), low consumption index (0.5 mL) and low limits of quantification and detection, 5.0 and 1.5 µg L-1, respectively, were obtained with the developed method. Practical application of method was tested on water samples, chocolate powder, Ginkgo biloba and sediment (certified reference material). On the basis of the results, the SiAlSn can be considered an effective adsorbent belonging to the class of CAF-SPE for Pb2+ determination from different matrices.

Carbon black (CB) grafted with 3-mercaptopropyltrimethoxysilane (3-MPTMS) was used as solid phase extractor for Cd2+ in a flow injection system coupled to flame atomic absorption spectrometry (FAAS). The influence of pH, buffer concentration, preconcentration flow rate and eluent concentration on preconcentration of Cd2+ were investigated by means of chemometric tools. The characterization of the adsorbent chemically modified was performed by Fourier transform infrared, scanning electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis, Raman spectroscopy and textural analysis. To perform the on-line preconcentration, 20.0 mL of a pH 7.0 Cd2+ solution at a flow rate of 4.0 mL min−1 was loaded through 30.0 mg of modified CB and then eluted with 1.0 mol L−1 HCl toward the FAAS instrument. The limits of detection and quantification were found to be 0.20 and 0.66 µg L−1, respectively. Addition and recovery tests carried out in real samples (mineral, tap and saline waters, and cigarette sample) and the analysis of certified reference material (TORT-2, lobster hepatopancreas reference) attested the applicability of proposed method.