Development of flow systems for sample preparation applied to agronomic studies: determination of stress signaling species and nitrogen fractionation in leaf tissues

• Grant number: 16/25333-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2017
• End date: April 30, 2019
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Fábio Rodrigo Piovezani Rocha
• Grantee: Thiago Linhares Marques
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 11/23498-9 - Advanced flow systems for technological, agronomical and environmental analysis, AP.TEM

Abstract

Analytical Chemistry is an important tool for the development of Agribusiness, which is one of the main sectors of Brazilian economy. However, the methods applied in agronomic studies are usually complex, laborious, expensive, time-consuming, and susceptible to systematic errors. Thus, improvements are necessary in order to apply these methods in routine analysis aiming at reliable results at lower costs. The determination of phytohormones such as salicylic acid and its conjugated forms and nitrogen fractionation in leaf tissues exemplify the previously mentioned disadvantages. Then, the goal of this project is the development of flow-based systems for sample preparation aiming at the previously mentioned applications. A microwave-assisted flow extraction system coupled to Sequential Injection Chromatography (SIC) with fluorimetric detection will be evaluated for determination of free and conjugated forms of salicylic acid. A flow system for ultrasound assisted sequential extraction coupled to a microwave-assisted and/or ultraviolet-assisted flow digestion system with spectrophotometric detection will be evaluated for nitrogen fractionation. The main challenge will be to perform the flow-based preparation of solid samples, which need to show appropriate particle size distribution for efficient and reproducible determination without clogging or increasing in backpressure. This will be overcome using appropriate devices and materials such as PTFE tubes and helicoidal reactors, syringe and peristaltic pumps, rotatory valves and reactional chambers with filters for sample retention. Therefore, development of simple, fast, reliable, and safe procedures that can be applied in routine laboratories is expected. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MARQUES, THIAGO L.; NOBREGA, JOAQUIM A.; ROCHA, FABIO R. P.. Flow-based solid sample preparation: Advantages, limitations, and challenges. TRAC-TRENDS IN ANALYTICAL CHEMISTRY, v. 118, p. 677-685, SEP 2019. (16/25333-0)

MARQUES, THIAGO L.; MORAES, LIZ MARY B.; ROCHA, FABIO R. P.. Systematic evaluation of sample preparation for fractionation of phytohormone salicylic acid in fresh leaves. Talanta, v. 208, FEB 1 2020. (16/25333-0)

MARQUES, THIAGO L.; SASAKI, MILTON K.; NUNES, LIDIANE C.; ROCHA, FABIO R. P.. Flow-Batch Sample Preparation for Fractionation of the Stress Signaling Phytohormone Salicylic Acid in Fresh Leaves. JOURNAL OF ANALYTICAL METHODS IN CHEMISTRY, v. 2020, JUL 17 2020. (16/25333-0)