Identification and quantification of microplastics using Nile Red staining.
We investigated the applicability of Nile Red (NR), a fluorescent dye, for microplastic analysis, and determined the optimal staining conditions. Five mg/L NR solution in n-hexane effectively stained plastics, and they were easily recognized in green fluorescence. The NR staining method was successfully applied to micro-sized polyethylene, polypropylene, polystyrene, polycarbonate, polyurethane, and poly(ethylene-vinyl acetate), except for polyvinylchloride, polyamide and polyester. The recovery rate of polyethylene (100-300μm) spiked to pretreated natural sand was 98% in the NR stating method, which was not significantly (p<0.05) different with FT-IR identification. The NR staining method was suitable for discriminating fragmented polypropylene particles from large numbers of sand particles in laboratory weathering test samples. The method is straightforward and quick for identifying and quantifying polymer particles in the laboratory controlled samples. Further studies, however, are necessary to investigate the application of NR staining to field samples with organic remnants.
Oil and POPs Research Laboratory, Korea Institute of Ocean Science and Technology, 41 Jangmok-1-gil, Geoje 53201, Republic of Korea; Department of Marine Environmental Sciences, Korea University of Science and Technology, Gajeong-ro, Daejeon 34113, Republic of Korea. Electronic address: wjshim@kiost.ac.kr.
Won Joon
WJ
Shim
Oil and POPs Research Laboratory, Korea Institute of Ocean Science and Technology, 41 Jangmok-1-gil, Geoje 53201, Republic of Korea; Department of Marine Environmental Sciences, Korea University of Science and Technology, Gajeong-ro, Daejeon 34113, Republic of Korea.
Young Kyoung
YK
Song
Oil and POPs Research Laboratory, Korea Institute of Ocean Science and Technology, 41 Jangmok-1-gil, Geoje 53201, Republic of Korea; Department of Marine Environmental Sciences, Korea University of Science and Technology, Gajeong-ro, Daejeon 34113, Republic of Korea.
Sang Hee
SH
Hong
Oil and POPs Research Laboratory, Korea Institute of Ocean Science and Technology, 41 Jangmok-1-gil, Geoje 53201, Republic of Korea; Department of Marine Environmental Sciences, Korea University of Science and Technology, Gajeong-ro, Daejeon 34113, Republic of Korea.
Mi
M
Jang
D005456:Fluorescent Dyes; D010078:Oxazines; D010969:Plastics; D020959:Polyethylene; D017550:Spectroscopy, Fourier Transform Infrared; D013194:Staining and Labeling; D014874:Water Pollutants, Chemical / Q000032:analysis*
D005456:Fluorescent Dyes; D010078:Oxazines; D010969:Plastics; D014874:Water Pollutants, Chemical; D020959:Polyethylene; C044808:nile red
Nile Red; identification; microplastics; staining