Near-infrared spectra of liquid and gas samples by diffuse reflectance employing benchtop and handheld spectrophotometers

Autor(es)

Paiva, Eduardo Maia ^[1] ; Ribessi, Rafael Luis ^[1] ; Rohwedder, Jarbas Jose Rodrigues ^[1]

Afiliação do(s) autor(es)

^[1] State Univ Campinas Unicamp, Inst Chem, Rua Monteiro Lobato 290, BR-13083862 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY; v. 264, JAN 5 2022.
• Citações Web of Science: 0

Resumo

This paper describes a new method to obtain NIR spectra of liquid and gas samples by diffuse reflectance, which is especially suitable for handheld spectrophotometers, since most of these instruments are designed to acquire spectrum using this geometry. The core of the method is a diffuse reflectance cell, which consists of a vial containing a mixture of the liquid or gas sample (rare medium) and a powder (dense medium). Using this strategy, no adaptation is required to measure spectra with most portable NIR spectrometers. This new method was used to obtain NIR spectra of several liquids and gases, which were compared with traditional transmittance spectra. As a proof of concept, measurements of biodiesel/ vegetable oil/diesel blends were used to build multivariate calibrations to predict the contents of biodiesel and vegetable oil in diesel blends using benchtop and handheld FT-NIR spectrophotometers. This lowcost method was demonstrated to be suitable for overcoming problems related to the handling of viscous samples and expand the applications with portable NIR instruments. (c) 2021 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 14/50951-4 - INCT 2014: Tecnologias Analíticas Avançadas
• Beneficiário: Celio Pasquini
• Modalidade de apoio: Auxílio à Pesquisa - Temático