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Heavy metals (e.g., Cd, Cu, Hg, Pb) at trace levels are proven toxic elements and can be the cause of human health disorders. 1,2 Because the main sources of these metals for humans are water and food, monitoring the heavy metal content in natural waters is of paramount importance.The cadmium contamination in environmental samples is generally lower than 5 ng mL -1 , so very sensitive techniques are required for determinations. Several analytical techniques exist for determining trace levels of cadmium. 3,4 Flow injection preconcentration techniques are useful for application in determining heavy metal ions by flame absorption atomic spectrometry (FAAS), providing a superior performance because they allow for the enhancement of sensitivity, separation of the analyte from the matrix and reduction of the risk of contamination. [5][6][7][8] The Cd 2+ preconcentration with solid phase extraction (SPE) technique using highly selective sorbentpacked columns has been described elsewhere.9-11 Compatible detection limits were obtained by the SPE technique.In recent years, the use of chemically modified silica gel matrixes with attached groups having a selective affinity for metal ions has been described. [12][13][14][15] A manual procedure with this sorbent-packed column has been proposed for Cd preconcentration. 12,15 However, the routine application of this procedure is limited by the time necessary for each analysis (100 min for each determination).This work describes the analytical performance of a flow injection system with online preconcentration on a sorbent minicolumn packed with 2-aminothiazole-modified silica gel (SiAT) for determining Cd in a series of river water samples. The material was initially tested with a synthetic aqueous solution containing Cd 2+ ; after that it was used in real samples. ExperimentalReagents, analytical solutions and samples All the solutions were prepared with high purity chemicals and distilled-deionized water (Milli-Q system, Millipore). The hydrochloric and nitric acids used were of the brand Suprapur quality (Merck).Cadmium standard solutions (5 -50 µg L -1 ) were prepared by stepwise dilution from a 1000 mg L -1 stock solution (Merck Titrisol) with Milli-Q treated water, acidified with nitric acid to pH 2.The mini-column (a 5 cm long, 3 mm i.d. glass tube) was drypacked with 100 mg of SiAT.Samples of river water (Tietê, Parapanema and Parana rivers, SP, Brazil) were collected and immediately filtered through a 0.45 µm membrane. After acidification (pH < 2.0) with 6.0 mol L -1 HNO3 solution, the samples were stored in highly purified PE containers. Aliquots of 100 mL of the water samples were digested by oxidation with UV-photolysis in the presence of 0.01% of H2O2, using a low-pressure Hg-lamp integrated to a closed quartz vessel. 17The aqueous extract resulting was poured into a 100 mL volumetric flask and this solution was diluted to the final volume with deionized water. Imperatriz, MA, Brasil A rapid and sensitive method was developed to determine trace levels of Cd 2+...

The shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora.

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