Industrialized powdered spices are widely used by the population in food preparation, although they are associated with several health problems. This relationship between spices and health problems can be explained due to the presence of some substances used to enhance the flavor and preserve them. Therefore, it is important to evaluate the metal content in these products, allowing their characterization. In this work, six metals (Zn, Fe, Ca, Mg, Na, and K) were determined in samples of dry industrialized spices that were sprayed and sold in sachets. Flame atomic absorption (FAAS) and emission (FAES) spectrometry were used to quantify the metals in the digestate obtained after the decomposition of the samples in a digester block. The following concentration ranges were found for the analyzed metals (mg Kg− 1): Zn (< LQ-15.53), Fe (10.82–205.3), Ca (27.45–1842), Mg (114.8–1374), Na (63739–268188) e K (1560-235864). These values were evaluated using principal component analysis (PCA) and Kohonen self-organizing maps (KSOMs) techniques. The multivariate analysis allowed the recognition of grouping trends according to the spice brands, which suggests the possibility of a base material, from which the flavors are differentiated.

Cloud point extraction (CPE) in association with graphite furnace atomic absorption spectrometry (GF AAS) was proposed for preconcentration and quantification of trace amounts of copper and cadmium in samples of saline produced formation water from petroleum exploration. The procedure was based on the formation of hydrophobic complexes of the analytes with 1,5-diphenylthiocarbazone (dithizone) in a micellar media of the surfactant (1,1,3,3-tetramethyl butyl) phenyl-polyethylene glycol (Triton X-114). Constrained mixture design was performed for the optimization of the proportions of the three solutions employed in the CPE: Triton X-114, dithizone, and buffer solution. Under the recommended conditions, the CPE GF AAS procedure allowed to obtain enrichment factors of 18 and 11 times, limits of quantification of 0.030 and 0.12 µg L-1 and precision, expressed as relative standard deviation (RSD, n = 8, 2.0 µg L-1), of 1.1 and 4.3% for copper and cadmium, respectively. The CPE GF AAS method was applied to the determination of copper and cadmium in samples of saline produced formation water from petroleum exploration, and its accuracy was accessed by analyzing certified reference material CASS-5 (Nearshore Seawater Reference Material for Trace Metals) from National Research Council (Canada).

Plant litter has several functions in a forest ecosystem. Studies about plant litter are of great importance to better understand and conserve ecological environments. The objective of this study was to investigate the concentration of metals (Fe, Co, Ca, Cu, Ni, Mg, Mn and Zn) in Caatinga plant litter in the southwest region of Bahia. Plant litter was collected in summer (January/2017) and winter (August/2017). Concentrations were determined by flame atomic absorption spectrometry (FAAS). The results were submitted to multivariate analysis, principal component analysis (PCA), and hierarchical cluster analysis (HCA). The average amount of plant litter found in January and August was 1190 and 1329 kg ha -1 , respectively. The twigs fraction provided the largest amount of biomass to the plant litter since this deposition occurred in greater quantity in August, a period of drought. Metal concentrations (g kg -1 ) in the analyzed samples ranged from 1.39-257 (Fe), < limit of quantification (LOQ)-0.269 (Co), 0.0036-0.61 (Cu), 1.39-8.76 (Ca), 0.0022-0.56 (Ni), 0.137-1.52 (Mg), 0.033-1.91 (Mn) and 0.0022-0.8 (Zn). The multivariate analysis showed that the composition of plant litter is altered seasonally.