The current research aims to introduce Layered Double Hydroxides (LDH) as nanomaterials to be used in agriculture, with particular reference to its use as storage and slow release matrix of nutrients and agrochemicals for plant growing. Structural characteristics, main properties, synthesis methods and characterization of LDH were covered in this study. Moreover, some literature data have been reported to demonstrate their potential for storage and slow release of nitrate, phosphate, agrochemicals, besides as being used as adsorbent for the wastewater treatment. This research aims to expand, in near future, the investigation field on these materials, with application in agriculture, increasing the interface between chemistry and agronomy.

The presence of rare earth elements (REE) in geological materials provides important information about the formation and the geochemical processes that rocks undergo. Therefore, there is a constant necessity for accurate data and reliable and fast analytical methods. However, the low concentrations of these elements typically found in rocks require quantification by sufficiently sensitive techniques, such as Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The preparation of these samples to the introduction in ICP-MS is a critical part of the process. Traditional wet dissolution methods, such as acid digestion or alkaline fusion followed by dissolution are mostly employed. The acid digestion requires a mixture of strong acids due to the presence of low soluble constituents common in rock samples, such as silicates or clays. The alkaline fusion is fast and efficient, but the dissolution of the melted material results in solutions with a high amount of total dissolved solids (TDS), which can be a problem due to the possibility of deposition in parts of the ICP-MS. Other instrumental approaches have been spread rapidly, as the coupling of a laser ablation accessory or an electrothermal vaporizer to the ICP-MS, as they can allow the direct sample introduction, or at least with minimum preparation. This paper presents a review of sample preparation methods, aimed at the quantification of rare earth elements by ICP-MS and focusing on works published in the last decade.