Creative Chemistry and Innovation Research Unit, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahasarakham University, Maha Sarakham 44150, Thailand.
Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.
Molecules. 2021 Dec 22;27(1):43. doi: 10.3390/molecules27010043.
A single-step preconcentration procedure using the in-situ formation of modified nickel-zinc-layered double hydroxides (LDHs) prior to high-performance liquid chromatography (HPLC) is investigated for the determination of neonicotinoid insecticide residues in honey samples. The LDHs could be prepared by the sequential addition of sodium hydroxide, sodium dodecyl sulfate, nickel nitrate 6-hydrate and zinc nitrate 6-hydrate, which were added to the sample solution. The co-precipitate phase and phase separation were obtained by centrifugation, and then the precipitate phase was dissolved in formic acid (concentrate) prior to HPLC analysis. Various analytical parameters affecting extraction efficiency were studied, and the characterization of the LDHs phase was performed using Fourier-transformed infrared spectroscopy and scanning electron microscopy. Under optimum conditions, the limit of detection of the studied neonicotinoids, in real samples, were 30 μg L, for all analytes, lower than the maximum residue limits established by the European Union (EU). The developed method provided high enrichment, by a factor of 35. The proposed method was utilized to determine the target insecticides in honey samples, and acceptable recoveries were obtained.
采用原位合成法制备了镍锌层状双氢氧化物（LDHs），并将其用于高效液相色谱（HPLC）前的预浓缩，用于蜂蜜样品中新型烟碱类杀虫剂残留的测定。LDHs 可通过顺序添加氢氧化钠、十二烷基硫酸钠、硝酸镍六水合物和硝酸锌六水合物到样品溶液中制得。通过离心得到共沉淀相和相分离，然后将沉淀相溶解在甲酸（浓缩）中，再进行 HPLC 分析。研究了影响萃取效率的各种分析参数，并采用傅里叶变换红外光谱和扫描电子显微镜对 LDHs 相进行了表征。在最佳条件下，所研究的新型烟碱类杀虫剂在实际样品中的检出限均为 30μg/L，均低于欧盟（EU）规定的最大残留限量。该方法的富集倍数高达 35 倍。该方法用于测定蜂蜜样品中的目标杀虫剂，获得了可接受的回收率。
