Charles University, Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry, Hlavova 2030/8, 12843, Prague 2, Czech Republic.
REQUIMTE/LAQV - Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007, Porto, Portugal.
Talanta. 2020 Sep 1;217:121068. doi: 10.1016/j.talanta.2020.121068. Epub 2020 Apr 23.
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 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.
一种新的电化学分析方法被开发用于检测木质基产品(WBPs)中的甲醛,该方法使用顶空液相吸附系统(HLAS)进行提取,然后通过未修饰的丝网印刷碳电极(SPCE)进行方波伏安法(SWV)检测。HLAS 是首次在此应用,它通过使用乙酰丙酮试剂作为接受溶液来捕获和衍生从样品中释放的甲醛。在铵盐存在下,甲醛与乙酰丙酮的产物是 3,5-二乙酰基-1,4-二氢卢剔啶(DDL),我们发现它在未修饰的 SPCE 上具有电化学活性,在+0.4 V 处产生选择性氧化峰。该方法的检测限和定量限分别为 0.57 和 1.89 mg kg,日内和日间精密度均低于 10%(相对标准偏差,RSD)。该方法用于测定七种 WBPs 中的甲醛含量,与开发的 HLAS-SPCE 方法和欧洲标准方法 EN 717-3 得到的结果相似,总分析时间显著缩短。所开发的 HLAS-SPCE 结合了使用新的挥发性样品制备程序,以及我们所知的在未修饰的 SPCE 上首次测定甲醛(作为衍生产物 DDL),为测定 WBPs 和其他样品中的甲醛提供了一种有前途的替代方法。