Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Pl, Liverpool, L3 5QA, UK.
Cowleigh Park Farm, Cowleigh Road, Malvern, WR13 5HJ, UK.
Sci Rep. 2022 Jun 11;12(1):9715. doi: 10.1038/s41598-022-13768-z.
Long-lasting insecticide-treated nets (LLINs) play a crucial role in preventing malaria transmission. LLINs should remain effective for at least three years, even after repeated washings. Currently, monitoring insecticides in LLINs is cumbersome, costly, and requires specialized equipment and hazardous solvents. Our aim was to develop a simple, high-throughput and low-resource method for measuring insecticides in LLINs. To extract insecticides, polyethylene-LLIN samples were heated at 85 °C for 45 min in a non-hazardous solvent mix containing dicyclohexylphthalate as an internal standard. The extraction solvent was reduced from 50 to 5 ml using a 0.2 g sample, 90% smaller than the recommended sample size. By optimizing HPLC chromatography, we simultaneously detected pyrethroid and pyriproxyfen insecticides with high sensitivity in LLIN's extract. The method can quantify levels ≥ 0.0015% permethrin, 0.00045% alpha-cypermethrin and 0.00025% pyriproxyfen (w/w) in polyethylene, allowing for insecticide tracking before and after the use of LLINs. This method can be used to assess LLINs with 1% pyriproxyfen (pyriproxyfen-LLIN) or 2% permethrin (Olyset® Net), 1% pyriproxyfen and 2% permethrin (Olyset® Duo), or 0.55% pyriproxyfen and 0.55% alpha-cypermethrin (Royal Gaurd®). One can run 120 samples (40 nets) simultaneously with high precision and accuracy, improving throughput and reducing labour, costs, and environmental impact.
长效杀虫剂处理蚊帐（LLINs）在防止疟疾传播方面发挥着至关重要的作用。LLINs 即使经过多次洗涤，也应至少保持三年的有效性。目前，监测 LLINs 中的杀虫剂既繁琐又昂贵，需要专门的设备和危险的溶剂。我们的目标是开发一种简单、高通量且资源需求低的方法来测量 LLINs 中的杀虫剂。为了提取杀虫剂，将聚乙烯-LLIN 样品在非危险溶剂混合物中加热至 85°C 45 分钟，其中包含邻苯二甲酸二环己酯作为内标。与推荐的样品量相比，提取溶剂从 50 毫升减少至 5 毫升，减少了 90%。通过优化高效液相色谱（HPLC）色谱，我们能够同时以高灵敏度检测 LLIN 提取物中的拟除虫菊酯和吡虫啉杀虫剂。该方法可以定量测量聚乙烯中≥0.0015%的氯菊酯、0.00045%的α-氯菊酯和 0.00025%的吡虫啉（w/w）的水平，从而可以在使用 LLINs 前后进行杀虫剂跟踪。该方法可用于评估含有 1%吡虫啉（吡虫啉-LLIN）或 2%氯菊酯（Olyset® Net）、1%吡虫啉和 2%氯菊酯（Olyset® Duo）或 0.55%吡虫啉和 0.55%α-氯菊酯（Royal Gaurd®）的 LLINs。该方法可以同时高精度和高准确度地处理 120 个样品（40 个蚊帐），从而提高通量，减少劳动力、成本和环境影响。
