Han Qiang, Aydan Tursunjan, Yang Liu, Zhang Xiaoqiong, Liang Qionglin, Ding Mingyu
Ministry of Education, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China.
College of Chemistry & Chemical Engineering, Xinjiang University, Urumqi 80046, China.
Anal Chim Acta. 2018 Jun 7;1009:48-55. doi: 10.1016/j.aca.2018.01.001. Epub 2018 Jan 19.
On-site sampling is an analytical approach that can ensure the accuracy of monitoring data and enhance the effectiveness of environmental protection measures. In the present work, an in-syringe solid-phase extraction (SPE) device was designed for on-site sampling of trace contaminants in environmental water samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Template assisted freeze casting followed by hydrazine vapor reduction approach was used to synthesize a hierarchical porous graphene aerogel (HPGA), which was used as the sorbent in the in-syringe SPE device. Environmental degradable pyrethroids were selected as the model analytes. Owing to the large specific surface area and hydrophobicity of HPGA, the target molecules could be completely extracted during one aspirating/dispensing cycle. The analytes were stable on the sorbent for at least 72 h when the device was stored under airtight and light-free conditions, and were not affected by the pH value of sample solution. All results demonstrated that the device could meet the requirements of on-site sampling. For practical application, the limits of detection were found to be in the range of 0.012-0.11 ng mL under the optimized conditions, and satisfactory recoveries in the range of 65.7-105.9% were obtained for the analysis of real samples. The results of this study demonstrate the immense potential of HPGA for the enrichment of trace environmental pollutants, and meanwhile promote the application of the in-syringe SPE technique as a promising candidate for on-site sampling.
现场采样是一种能够确保监测数据准确性并提高环境保护措施有效性的分析方法。在本研究中，设计了一种注射器内固相萃取（SPE）装置，用于环境水样中痕量污染物的现场采样，随后进行气相色谱 - 质谱（GC - MS）分析。采用模板辅助冷冻铸造法结合肼蒸汽还原法合成了一种分级多孔石墨烯气凝胶（HPGA），并将其用作注射器内SPE装置中的吸附剂。选择环境可降解拟除虫菊酯作为模型分析物。由于HPGA具有较大的比表面积和疏水性，目标分子能够在一个抽吸/分配循环中被完全萃取。当装置在气密和无光条件下储存时，分析物在吸附剂上至少稳定72小时，并且不受样品溶液pH值的影响。所有结果表明该装置能够满足现场采样的要求。在实际应用中，优化条件下的检测限在0.012 - 0.11 ng mL范围内，对实际样品分析获得了65.7 - 105.9%的满意回收率。本研究结果证明了HPGA在富集痕量环境污染物方面的巨大潜力，同时推动了注射器内SPE技术作为现场采样的一种有前景的候选方法的应用。
