Grabarczyk Malgorzata, Fialek Marzena, Wardak Cecylia
Department of Analytical Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University, 20-031 Lublin, Poland.
Molecules. 2024 Nov 21;29(23):5501. doi: 10.3390/molecules29235501.
This paper proposes a simple, environmentally friendly, and efficient procedure for preparing natural water samples for the voltammetric determination of trace amounts of Se(IV). The method is based on premixing a sample with Amberlite XAD-7 resin at 50 °C. The composition of the 10 mL solution consists of the sample to be analysed, 0.1 mol L of acetate buffer at pH = 4.0, and 0.5 g of Amberlite XAD-7. After 2 min of stirring, a voltammetric measurement is carried out using a fixed bismuth microelectrode using the following potentials: -2.5 V for 2 s and -0.55 V for 30 s. The voltammetry is recorded by varying the potential from -400 mV to -1000 mV. An undisturbed Se(IV) signal is obtained in the presence of 10 mg L of Triton X-100, 5 mg L of SDS, 10 mg L of CTAB, 5 mg L of Rhamnolipid, 5 mg L of HA, 10 mg L of FA, and 2 mg L of NOM. The validity of the developed procedure is checked by analysing the certified reference materials SPS-SW1 (surface water) and TM-25.5 (Lake Ontario water) additionally enriched with surfactants and humic substances.
本文提出了一种简单、环保且高效的用于伏安法测定痕量硒（IV）的天然水样制备方法。该方法基于在50°C下将样品与Amberlite XAD - 7树脂预混合。10 mL溶液的组成包括待分析的样品、pH = 4.0的0.1 mol/L醋酸盐缓冲液和0.5 g Amberlite XAD - 7。搅拌2分钟后，使用固定铋微电极在以下电位下进行伏安测量：-2.5 V持续2 s，-0.55 V持续30 s。通过将电位从-400 mV变化到-1000 mV来记录伏安图。在存在10 mg/L Triton X - 100、5 mg/L SDS、10 mg/L CTAB、5 mg/L鼠李糖脂、5 mg/L腐殖酸、10 mg/L富里酸和2 mg/L天然有机物的情况下获得了不受干扰的硒（IV）信号。通过分析额外添加了表面活性剂和腐殖物质的有证标准物质SPS - SW1（地表水）和TM - 25.5（安大略湖水）来检验所开发方法的有效性。
