ANALYSIS

It is a basic tool that allows soil quality knowledge from an agricultural and environmental point of view in order to improve crop fertility or solve specific problems (salinity, acidity, pollution, etc.).

The main soil testing includes: basic analysis (pH, electrical conductivity, organic matter, nitrogen, Olsen-phosphorus, available potassium, carbonates and texture), available nutrients and available micronutrients, cation exchange capacity, salinity in saturate paste extract, nitrate and ammonium contents, aqua regia extractable metals and trace elements.

It is important to know water quality for irrigation in order to prevent salinity or toxicity problems, as well as deciding the most suitable irrigation systems and doses. The SA main water determinations are: pH, electrical conductivity, chloride, nitrate, ammonium, alkalinity, solids, sodium, potassium, calcium, magnesium, sulfate, microelements and trace elements.

The study of these samples is a prerequisite for their use, especially when considering the use of waste from various sources (compost, sludge, etc.). SA mainly determines: pH, electrical conductivity, organic matter, nitrogen, nutrients, microelements and trace elements.

Plant analysis is an effective method to estimate nutritional status and crop nutrient requirements. The information provided by foliar analysis is a good complement to soil analysis for an agricultural farm or an experimental trial. In this case, SA offers the determination of Kjeldahl-N, macro and micronutrients, and trace elements. In addition, SA department carries out metals determination in all types of agricultural and environmental samples.

The SA has two oven for the dissolution of solid samples through microwave-assisted digestion.

The automatic segmented flow analyzer allows the analysis of a large number of parameters (nitrogen, nitrate, nitrite, ammonium, chloride, phosphate, P-Olsen, sulfate, cyanide, etc.) in multiple types of samples (water, soil, plants, fertilizers, amendments, etc.). All of them are of great interest from an agricultural and environmental point of view, and the autoanalyzer displays results with great accuracy and low detection limits, in a short time and with low reagents consumption.

It allows the determination of total carbon, inorganic carbon, organic carbon (TOC) and total nitrogen present in liquid samples. Total carbon is measured by high temperature catalytic oxidation followed by non-dispersive infrared detection of CO₂. For the case of inorganic carbon, the samples are HCl acidified and sparged with a carrier gas (purified air) in order to convert the inorganic carbon to CO₂. Organic C is determined by the difference between total and inorganic C. Nitrogen is thermally decomposed in a combustion tube and it is detected by chemiluminescence.

This equipment is used to determine the total carbon and nitrogen content in solid or semi-liquid samples by burning the sample in pure oxygen at 1200 ᵒC. It has an autosampler and is capable of determining nitrogen (TN), total carbon (TC), total inorganic carbon (TIC) and total organic carbon (TOC).

This instrument allows the determination of organic nitrogen by Kjeldahl method. It is done quickly, as the distillation and titration are carried out in a single operation which is automatic and safe for the operator. It is used by boiling the sample with concentrated sulfuric acid and a catalyst, so that the oxidative destruction of the organic matter present in the sample and the decomposition of organic nitrogen to ammonia takes place. Subsequently, the ammonium is steam distillate and determined by titration.

Inductively coupled plasma atomic emission spectroscopy (ICP-OES) is a multielemental analysis technique capable of determining and quantifying most of the elements of the periodic table (with the exception of C, N, O, H, halogens and noble gases), in a wide range of concentrations and simultaneously. It allows the analysis of a wide range of both liquid and solid samples.

Inductively coupled plasma source mass spectrometry (ICP-MS) is a multielemental and isotopic inorganic analysis technique capable of determining and quantifying most of the elements of the periodic table at very low concentration levels. It can also carry out isotopic composition quantification and trace isotope stability studies.

The X-ray fluorescence spectrometry analyzer (XRF) is a powerful and portable unit for complete inspection in the environment in order to identify metals in soil samples, sediments, filters, etc. (around 10 mg/kg concentrations). The XRF analyzer is an advanced technology for monitoring extensive sites, for rapid analysis of containers or soils bags, sediments, metal cores, dusty cloths, surfaces and filters. The mapping of zones is facilitated, allowing a previous selection of the more representative samples in places of wide extension or variability, or the determination in samples that, due to their value, do not can be altered or taken to the laboratory, since it is a not destructive technique.