Fluorescence EEM data from PAHs in cachaça suported on nylon membranes

Description

Fluorescence EEM spectra of cachaça extracts were concentrated on nylon membranes. The information obtained from these spectra was utilized in the construction of a calibration curve, the execution of validation tests, the calculation of the limit of blank (LOB), the calculation of the limit of detection (LOD), and the optimization of the experiment.

Steps to reproduce

For calibration set, five calibration mixtures containing benzo[a]pyrene (BaP), dibenz[a,h]anthracene (DahA), benzo[b]fluoranthene (BbF), and benzo[g,h,i]perylene (BghiP) were prepared by diluting stock solutions in 38% ethanol to final concentrations ranging from 24 to 120 ng·L⁻¹ for BaP, DahA, and BghiP, and 45 to 225 ng·L⁻¹ for BbF. For validation set, six commercially available unaged cachaça samples were spiked with three different PAH mixtures at concentrations ranging from 36-84 ng·L⁻¹ for BaP, DahA, and BghiP, and 68-158 ng·L⁻¹ for BbF. Sample preparation involved dilution to 38% ethanol followed by a two-stage nylon membrane (0.45 μm) filtration process using a custom positive pressure system. The procedure comprises two sequential filtration steps. Initially, 50 mL cachaça samples are filtered through a nylon membrane. This step retains both PAHs and matrix interferences, such as organic matter and particulates, which can compromise fluorescence spectral measurements. To address this issue, the used membrane undergoes a solvent extraction process with 4.5 mL of acetonitrile. Furthermore, an additional 4.0 mL of ultrapure water are also found to pass through the membrane. The filtrate is transferred to a 50 mL volumetric flask and completed to volume with ultrapure water, promoting selective elution of the PAHs. The filtrate was collected in a 50 mL flask and made up with ultrapure water. This solution was filtered using the filtration system and a new membrane. Following 40 minutes of drying at room temperature, fluorescence measurements were performed directly on the membranes using a Cary Eclipse spectrofluorometer with optimized parameters (excitation: 250-306 nm; emission: 380-480 nm; steps: 2 nm; excitation and emission monochromator slits: 10 and 2.5 nm, respectively).

Institutions

• Universidade Federal da Paraiba

  PB, Joao Pessoa

Categories

Funders

• Coordenação de Aperfeicoamento de Pessoal de Nível Superior

  Federal District, Brazil
• Fundação de Apoio à Pesquisa do Estado da Paraíba

  Paraíba, Brazil
• Financiadora de Estudos e Projetos

  Rio de Janeiro, Brazil

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