A new electroanalytical methodology for the determination of formaldehyde in wood-based products

Pavel Dvořák; Rui Miguel Ramos; Vlastimil Vyskočil; José António Rodrigues

doi:10.1016/j.talanta.2020.121068

A new electroanalytical methodology for the determination of formaldehyde in wood-based products

Talanta. 2020 Sep 1:217:121068. doi: 10.1016/j.talanta.2020.121068. Epub 2020 Apr 23.

Authors

Pavel Dvořák¹, Rui Miguel Ramos², Vlastimil Vyskočil¹, José António Rodrigues³

Affiliations

¹ Charles University, Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry, Hlavova 2030/8, 12843, Prague 2, Czech Republic.
² REQUIMTE/LAQV - Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007, Porto, Portugal. Electronic address: rui.ramos@fc.up.pt.
³ REQUIMTE/LAQV - Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007, Porto, Portugal.

PMID: 32498846
DOI: 10.1016/j.talanta.2020.121068

Abstract

A new electroanalytical methodology was developed for the sensitive and selective determination of formaldehyde in wood-based products (WBPs), featuring an extraction process using a Headspace Liquid Acceptor System (HLAS), and detection by square-wave voltammetry (SWV) on unmodified screen-printed carbon electrodes (SPCEs). HLAS, here presented for the first time, captures and derivatizes formaldehyde released from the sample by using the acetylacetone reagent as acceptor solution. The product of formaldehyde with acetylacetone, in the presence of ammonium salt, is 3,5-diacetyl-1,4-dihydrolutidine (DDL) which we have found to be electrochemically active at unmodified SPCEs, generating a selective oxidation peak at +0.4 V. Detection and quantification limits of 0.57 and 1.89 mg kg^-1 were obtained, together with intra- and inter-day precisions below 10% (as relative standard deviation, RSD). The methodology was used to determine formaldehyde content in seven WBPs, with similar results being obtained by the developed HLAS-SPCE method and the European standard method EN 717-3, with a profound reduction of total analysis time. The developed HLAS-SPCE combines the use of a new sample preparation procedure for volatiles with, as far as we know, the first determination of formaldehyde (as the derivative product, DDL) on unmodified SPCEs, offering a promising alternative for the determination of formaldehyde in WBPs and other samples.

Keywords: Electroanalysis; Indoor air quality; Sample preparation; Screen-printed electrodes; Wood-based products.