X-ray fluorescence in Member States: Venezuela

The direct analysis of biological samples is the main research challenge of the scientific group at the Unidad de Analisis Instrumental of the Agronomy Faculty, Universidad Centro Occidental Lisandro Alvarado, (UCLA) Edo. Lara, Venezuela. The technique of total reflection X-ray fluorescence (TXRF) plays an important role in the scientific activities of the laboratory. In this field, the research is devoted to the design, development, evaluation and application of methods for the analysis of biological and related samples, such as biological tissues, fluids, biota, soil and water samples. The studies involve the evaluation of feasibility for direct determination of analytes, the in situ (in quartz sample holder) preparation techniques, the in situ pre-concentration and speciation among others studies. The methods are developed for the application in clinical studies, agronomy, environmental monitoring, bioremediation, statistical processing of data and neural network applications. The following projects are described: Direct analysis of biological samples by TXRF; Determination of calcium, potassium, manganese, iron, cooper and zinc levels in representative samples of two onion cultivars using TXRF and ultrasound extraction procedure; Evaluation of vermicompost as bioadsorbent substrate of Pb, Ni, V and Cr for waste waters remediation using total reflection X-ray fluorescence; Determination by TXRF of total As in onion plants growing in contaminated substrates