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塑料制品在我们的生活中无处不在。2017年,全球塑料产量上升至3.35亿吨[1]。最常见的塑料制品包括聚乙烯(PE)、聚丙烯(PP)、聚氯乙烯(PVC)、聚对苯二甲酸乙二酯(PET)、聚苯乙烯(PS)等。关于海洋中塑料的研究最早发表于20世纪70年代 [2]。在2004年,Thompson等[3]首次提出微塑料的概念,并引起了广泛关注。目前的研究表明微塑料存在于海洋环境[4-5]、淡水环境[6-9]、沉积物[10-11]、土壤[12-13]以及生物体内[14-15]。微塑料在被生物摄食后可造成挤压、占位等,从而导致生物摄食效率降低、生长缓慢、受伤或死亡等 [16-17]。微塑料本身也会释放塑化剂、阻燃剂、抗氧化剂等有毒物质 [18-22] 。此外,微塑料表面还能吸附环境中的疏水性有机污染物,在被水生生物摄食后,会对生物体产生毒性效应 [23-25] 。
准确、高效的分析方法是研究微塑料的环境行为及生态毒理学效应的关键前提。欧盟海洋战略框架指令(MSFD)[26]以及美国国家海洋和大气管理局[27](NOAA)分别发布了监测海洋环境中微塑料的实验方法。然而,目前微塑料的提取和分离方法尚未标准化。
本文综述了已有研究报道的水样、土壤和沉积物、水生生物样品中微塑料的前处理方法,并针对现有方法的优缺点进行比较(表1),对进一步的研究方向进行了讨论。
微塑料的提取分离方法研究进展
Research progress on the extraction and separation methods of microplastics
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摘要: 微塑料作为海洋环境和陆生生态系统中的新型污染物,引起了广泛关注。然而目前微塑料的分析方法尚未标准化,不同研究结果间可比性较低。如何准确、高效地提取分离样品中的微塑料,是探究微塑料的环境行为及生态毒理学效应的关键前提。本文系统地综述了环境样品和水生生物样品中微塑料的前处理分析方法,包括筛分过滤法、密度分离法、消解法以及文献报道的其他方法,并对不同方法的优缺点及研究趋势进行了讨论和分析。结合不同前处理方法的优势,开展多种方法组合、比较等研究有利于微塑料分析方法的标准化。Abstract: Microplastic as an emerging pollutant in the marine environment and terrestrial ecosystems has attracted widespread attention. However, the analysis methods of microplastics have not been standardized at present, which hampered the comparability between different research results. How to accurately and efficiently extract microplastics in samples is a crucial prerequisite for exploring the environmental behavior and ecotoxicological effects of microplastics. The pretreatment analysis methods of microplastics in environmental samples and aquatic biological samples were systematically reviewed in this paper, including sieve filtration method, density separation method, digestion method and other methods reported in the literature. Besides, the advantages and disadvantages of different methods and research trends were discussed. Combining the advantages of different pretreatment methods, carrying out studies with various method combinations and comparisons is conducive to the standardization of microplastic analysis methods.
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Key words:
- microplastics /
- extraction and separation /
- flotation /
- density separation /
- digestion
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表 1 样品前处理方法汇总
Table 1. Summary of methods for sample pretreatment.
前处理方法
Pretreatment methods样品基质
Sample matrix优点
Advantages缺点
Disadvantage参考文献
Reference筛分过
滤法过滤筛分 水、固体样品浮选上清液 可快速分离;通过不同孔径滤网,
可对微塑料按照粒径分类没有标准化的孔径尺寸,
不同研究可比性低[4, 28-30] 密度分
离法NaCl 水、土、沉积物、
生物无毒、无害、成本低 对高密度微塑料提取效率低 [26, 27, 31- 32] NaI 水、土、沉积物、
生物密度高、安全、可重复使用、
提取效率高价格昂贵 [31, 33-36] ZnCl2 水、土、沉积物、
生物密度高、提取效率高、
成本低腐蚀性、危害性 [32, 37-40] 甲酸钾 水、土、沉积物、
生物稳定性好、成本低 目前应用研究较少 [41-42] 聚钨酸钠 水、土、沉积物、
生物密度高、成本较低 吸湿性强 [43-44] 油 土、沉积物 成本低、易操作 需要对微塑料进行进一步清洗;
目前应用研究较少[45-47] 密度分离
浮选装置土、沉积物 直接分离,能够有效
减小样品量需要与密度浮选液结合,
还需进一步验证及优化[32, 40, 48] 消解法 酸消解
(HCl)水、土、沉积物、
生物− 不能破坏所有有机质 [49-52] 酸消解
(HNO3)水、土、沉积物、
生物能够去除大部分有机质 可能会造成PET等聚合物溶解 [34, 49, 53-56] 碱消解
(NaOH/KOH)水、土、沉积物、
生物能去除大部分有机质;对大
部分聚合物没有破坏性可能使塑料变色;沉积残留物
对光谱信号产生干扰[51-54, 56-61] 氧化消解
(H2O2)水、土、沉积物、
生物能去除大部分有机质; 对部分聚合物有破坏性 [31, 50, 52, 59, 62] 氧化消解
(Fenton试剂)水、土、沉积物、
生物能去除有机质、提取效率高、
对光谱信号无影响− [27, 63] 酶消解 水、土、沉积物、
生物危害小、
不会对聚合物造成损害成本高、耗时长 [51-52, 63-64] 其他
方法静电分离装置 沉积物 能够将样品量减小99% 不适用于少量样品 [65] 磁提取法 水、沉积物 对大部分聚合物提取效率高 对于复杂样品需与其他方法结合,
更适用于饮用水等基质简单
的样品;需进一步优化[66] -
[1] PlasticsEurope, Plastics - the Facts 2017: An analysis of European plastics production, demand and waste data[R], 2017. Available from: https://www.plasticseurope.org/application/files/5715/1717/4180/Plastics_the_facts_2017_FINAL_for_website_one_page.pdf [2] CARPENTER E, SMITH K L. Plastics on the Sargasso Sea surface [J]. Science, 1972, 175(4027): 1240-1241. doi: 10.1126/science.175.4027.1240 [3] THOMPSON R C, OLSEN Y, MITCHELL R P, et al. Lost at sea: Where is all the plastic? [J]. Science, 2004, 304(5672): 838-838. doi: 10.1126/science.1094559 [4] HIDALGO-RUZ V, GUTOW L, THOMPSON R C, et al. Microplastics in the marine environment: A review of the methods used for identification and quantification [J]. Environmental Science & Technology, 2012, 46(6): 3060-3075. [5] ZHANG W W, ZHANG S F, ZHANG Z Y, et al. Microplastic pollution in the surface waters of the Bohai Sea, China [J]. Environmental Pollution, 2017, 231: 541-548. doi: 10.1016/j.envpol.2017.08.058 [6] EERKES-MEDRANO D, THOMPSON R C, ALDRIDGE D C. Microplastics in freshwater systems: A review of the emerging threats, identification of knowledge gaps and prioritisation of research needs [J]. Water Research, 2015, 75: 63-82. doi: 10.1016/j.watres.2015.02.012 [7] BLETTLER M C M, ABRIAL E, KHAN F R, et al. Freshwater plastic pollution: Recognizing research biases and identifying knowledge gaps [J]. Water Research, 2018, 143: 416-424. doi: 10.1016/j.watres.2018.06.015 [8] LI J Y, LIU H H, CHEN J P. Microplastics in freshwater systems: A review on occurrence, environmental effects, and methods for microplastics detection [J]. Water Research, 2018, 137: 362-374. doi: 10.1016/j.watres.2017.12.056 [9] KOELMANS A A, MOHAMED N H, HERMSEN E, et al. Microplastics in freshwaters and drinking water: Critical review and assessment of data quality [J]. Water Research, 2019, 155: 410-422. doi: 10.1016/j.watres.2019.02.054 [10] PRATA J C, DA C J P, DUARTE A C, et al. Methods for sampling and detection of microplastics in water and sediment: A critical review [J]. Trends in Analytical Chemistry, 2019, 110: 150-159. doi: 10.1016/j.trac.2018.10.029 [11] DING L, MAO R F, GUO X T, et al. Microplastics in surface waters and sediments of the Wei River, in the northwest of China [J]. Science of the Total Environment, 2019, 667: 427-434. doi: 10.1016/j.scitotenv.2019.02.332 [12] HE D F, LUO Y M, LU S B, et al. Microplastics in soils: Analytical methods, pollution characteristics and ecological risks [J]. Trends in Analytical Chemistry, 2018, 109: 163-172. doi: 10.1016/j.trac.2018.10.006 [13] MÖLLER J N, LÖDER M G J, LAFORSCH C. Finding microplastics in soils: A review of analytical methods [J]. Environmental Science & Technology, 2020, 54(4): 2078-2090. [14] RIBEIRO F, O'BRIEN J W, GALLOWAY T, et al. Accumulation and fate of nano- and micro-plastics and associated contaminants in organisms [J]. Trends in Analytical Chemistry, 2018, 111: 139-147. [15] SHAHABALDIN R, JUNBOUM P, MOHD F M D, et al. Microplastics pollution in different aquatic environments and biota: A review of recent studies [J]. Marine Pollution Bulletin, 2018, 133: 191-208. doi: 10.1016/j.marpolbul.2018.05.022 [16] BROWNE M A, DISSANAYAKE A, GALLOWAY T, et al. Ingested microscopic plastic translocates to the circulatory system of the Mussel, Mytilus edulis (L. ) [J]. Environmental Science & Technology, 2008, 42(13): 5026-5031. [17] DERRAIK J G B. The Pollution of the marine environment by plastic debris: A review [J]. Marine Pollution Bulletin, 2002, 44(9): 842-852. doi: 10.1016/S0025-326X(02)00220-5 [18] TEUTEN E L, SAQUING J M, KNAPPE D R, et al. Transport and release of chemicals from plastics to the environment and to wildlife [J]. Philosophical transactions - Royal Society. Biological Sciences, 2009, 364(1526): 2027-2045. doi: 10.1098/rstb.2008.0284 [19] SUHRHOFF T J, SCHOLZ-BOTTCHER B M. Qualitative impact of salinity, UV radiation and turbulence on leaching of organic plastic additives from four common plastics - A lab experiment [J]. Marine Pollution Bulletin, 2016, 102(1): 84-94. doi: 10.1016/j.marpolbul.2015.11.054 [20] KOELMANS A A, BESSELING E, FOEKEMA E M. Leaching of plastic additives to marine organisms [J]. Environmental Pollution, 2014, 187: 49-54. doi: 10.1016/j.envpol.2013.12.013 [21] ROCHMAN C M, HOH E, HENTSCHEL B T, et al. Long-term field measurement of sorption of organic contaminants to five types of plastic pellets: implications for plastic marine debris [J]. Environmental Science & Technology, 2013, 47(3): 1646-1654. [22] LIU X M, SHI H H, XIE B, et al. Microplastics as both a sink and a source of Bisphenol A in the marine environment [J]. Environmental Science & Technology, 2019, 53(17): 10188-10196. [23] ROCHMAN C M, MANZANO C, HENTSCHEL B T, et al. Polystyrene plastic: A source and sink for polycyclic aromatic hydrocarbons in the marine environment [J]. Environmental Science & Technology, 2013, 47(24): 13976-13984. [24] WARDROP P, SHIMETA J, NUGEGODA D, et al. Chemical pollutants sorbed to ingested microbeads from personal care products accumulate in fish [J]. Environmental Science & Technology, 2016, 50(7): 4037-4044. [25] SONG X W, WU X F, SONG X P, et al. Sorption and desorption of petroleum hydrocarbons on biodegradable and nondegradable microplastics [J]. Chemosphere, 2020,273: 128553. [26] MSFD Technical Subgroup on Marine Litter, Guidance on monitoring of marine litter in european seas. A guidance document within the common implementation strategy for the marine strategy framework directive[M]. European Commission, 2013. [27] MASURA J, BAKER J, FOSTER G, et al. Laboratory methods for the analysis of microplastics in the marine environment: Recommendations for quantifying synthetic particles in waters and sediments[R], NOAA Technical Memorandum, 2015. Available from: https://marinedebris.noaa.gov/sites/ default/files/publications-files/noaa_microplastics_methods_manual.pdf. [28] CLAESSENS M, MEESTER S D, LANDUYT L V, et al. Occurrence and distribution of microplastics in marine sediments along the Belgian coast [J]. Marine Pollution Bulletin, 2011, 62(10): 2199-2204. doi: 10.1016/j.marpolbul.2011.06.030 [29] KUSUI T, NODA M. International survey on the distribution of stranded and buried litter on beaches along the Sea of Japan [J]. Marine Pollution Bulletin, 2003, 47(1/6): 175-179. [30] SUL J A I D, SPENGLER A, COSTA M F. Here, there and everywhere. Small plastic fragments and pellets on beaches of Fernando de Noronha (Equatorial Western Atlantic) [J]. Marine Pollution Bulletin, 2009, 58(8): 1236-1238. doi: 10.1016/j.marpolbul.2009.05.004 [31] NUELLE M T, DEKIFF J H, REMY D, et al. A new analytical approach for monitoring microplastics in marine sediments [J]. Environmental Pollution, 2014, 184: 161-169. doi: 10.1016/j.envpol.2013.07.027 [32] IMHOF H K, SCHMID J, NIESSNER R, et al. A novel, highly efficient method for the separation and quantification of plastic particles in sediments of aquatic environments [J]. Limnology & Oceanography Methods, 2012, 10: 524-537. [33] CRAWFORD C B, QUINN B. 9-Microplastic separation techniques[M]. Microplastic Pollutants. Amsterdam: Elsevier Science, 2017: 203-218. [34] CLAESSENS M, VAN C L, VANDEGEHUCHTE M B, et al. New techniques for the detection of microplastics in sediments and field collected organisms [J]. Marine Pollution Bulletin, 2013, 70(1/2): 227-233. [35] KEDZIERSKI M, LE T V, C G, et al. Efficient microplastics extraction from sand. A cost-effective methodology based on sodium iodide recycling [J]. Marine Pollution Bulletin, 2017, 115(1/2): 120-129. [36] QUINN B, MURPHY F, EWINS C. Validation of density separation for the rapid recovery of microplastics from sediment [J]. Analytical Methods, 2016, 9(9): 1491-1498. [37] DRIS R, IMHOF H, SANCHEZ W, et al. Beyond the ocean: contamination of freshwater ecosystems with (micro-)plastic particles [J]. Environmental Chemistry, 2015, 12(5): 539-550. doi: 10.1071/EN14172 [38] IMHOF H K, WIESHEU A C, ANGER P M, et al. Variation in plastic abundance at different lake beach zones-A case study [J]. Science of the Total Environment, 2017, 613/614: 530-537. [39] HORTON A A, SVENDSEN C, WILLIAMS R J, et al. Large microplastic particles in sediments of tributaries of the River Thames, UK-Abundance, sources and methods for effective quantification [J]. Marine Pollution Bulletin, 2016, 114(1): 218-226. [40] COPPOCK R L, COLE M, LINDEQUE P K, et al. A small-scale, portable method for extracting microplastics from marine sediments [J]. Environmental Pollution, 2017, 230: 829-837. doi: 10.1016/j.envpol.2017.07.017 [41] ZHANG K, SU J, XIONG X, et al. Microplastic pollution of lakeshore sediments from remote lakes in Tibet plateau, China [J]. Environmental Pollution, 2016, 219: 450-455. doi: 10.1016/j.envpol.2016.05.048 [42] XIONG X, ZHANG K, CHEN X C, et al. Sources and distribution of microplastics in China's largest inland lake - Qinghai Lake [J]. Environmental Pollution, 2018, 235: 899-906. doi: 10.1016/j.envpol.2017.12.081 [43] CORCORAN P L, BIESINGER M C, GRIFI M. Plastics and Beaches: A Degrading Relationship [J]. Marine Pollution Bulletin, 2009, 58(1): 80-84. doi: 10.1016/j.marpolbul.2008.08.022 [44] PAGTER E, FRIAS J, NASH R. Microplastics in Galway Bay: A comparison of sampling and separation methods [J]. Marine Pollution Bulletin, 2018, 135: 932-940. doi: 10.1016/j.marpolbul.2018.08.013 [45] CRICHTON E M, NOL M, GIES E A, et al. A novel, density-independent and FTIR-compatible approach for the rapid extraction of microplastics from aquatic sediments [J]. Analytical Methods, 2017, 9(9): 1419-1428. doi: 10.1039/C6AY02733D [46] MANI T, FREHLAND S, KALBERER A, et al. Using castor oil to separate microplastics from four different environmental matrices [J]. Analytical Methods, 2019, 11(13): 1788-1794. doi: 10.1039/C8AY02559B [47] KARLSSON T M, VETHAAK A D, ALMROTH B C, et al. Screening for microplastics in sediment, water, marine invertebrates and fish: Method development and microplastic accumulation [J]. Marine Pollution Bulletin, 2017, 122(1/2): 403-408. [48] ZOBKOV M B, ESIUKOVA E E. Evaluation of the munich plastic sediment separator efficiency in extraction of microplastics from natural marine bottom sediments [J]. Limnology & Oceanography Methods, 2017, 15(11): 967-978. [49] DESFORGES J P W, GALBRAITH M, ROSS P S. Ingestion of microplastics by Zooplankton in the Northeast Pacific Ocean [J]. Archives of Environmental Contamination & Toxicology, 2015, 69(3): 320-330. [50] ZHAO S Y, DANLEY M, WARD J E, et al. An approach for extraction, characterization and quantitation of microplastic in natural marine snow using Raman microscopy [J]. Analytical Methods, 2016, 9(9): 1470-1478. [51] MAES T, JESSOP R, WELLNER N, et al. A rapid-screening approach to detect and quantify microplastics based on fluorescent tagging with Nile Red [J]. Scientific Reports, 2017, 7: 44501. doi: 10.1038/srep44501 [52] COLE M, LINDEQUE P, HALSBAND C, et al. Microplastics as contaminants in the marine environment: A review [J]. Marine Pollution Bulletin, 2011, 62(12): 2588-2597. doi: 10.1016/j.marpolbul.2011.09.025 [53] CATARINO A I, THOMPSON R, SANDERSON W, et al. Development and optimization of a standard method for extraction of microplastics in mussels by enzyme digestion of soft tissues [J]. Environmental Toxicology and Chemistry, 2017, 36(4): 947-951. doi: 10.1002/etc.3608 [54] DEHAUT A, CASSONE A L, FRERE L, et al. Microplastics in seafood: Benchmark protocol for their extraction and characterization [J]. Environmental Pollution, 2016, 215: 223-233. doi: 10.1016/j.envpol.2016.05.018 [55] NAIDOO T, GOORDIYAL K, GLASSOM D, Are nitric acid (HNO3) digestions efficient in isolating microplastics from Juvenile Fish? [J]. Water Air & Soil Pollution, 2017, 228(12): 470. [56] MUNNO K, HELM P A, JACKSON D A, et al. Impacts of temperature and selected chemical digestion methods on microplastic particles [J]. Environmental Toxicology & Chemistry, 2017, 37(1): 91-98. [57] 李陵云, 朱静敏, 李佳娜, 等. 水生生物样品中微塑料的提取和分离方法综述 [J]. 海洋环境科学, 2019, 38(2): 187-191. doi: 10.12111/j.mes20190204 LI L L, ZHU J M, LI J N, et al. Review on methods for extraction and isolation of microplastics in aquatic organisms [J]. Marine Environmental Science, 2019, 38(2): 187-191(in Chinese). doi: 10.12111/j.mes20190204
[58] FOEKEMA E M, GRUIJTER C D, MERGIA M T, et al. Plastic in North Sea Fish [J]. Environmental Science & Technology, 2013, 47(15): 8818-8824. [59] QIU Q X, TAN Z, WANG J D, et al. Extraction, enumeration and identification methods for monitoring microplastics in the environment [J]. Estuarine Coastal & Shelf Science, 2016, 176: 102-109. [60] KUHN S, WERVEN V B, OYEN V A, et al. The use of potassium hydroxide (KOH) solution as a suitable approach to isolate plastics ingested by marine organisms [J]. Marine Pollution Bulletin, 2017, 115(1/2): 86-90. [61] WAGNER J, WANG Z M, GHOSAL S, et al. Novel method for the extraction and identification of microplastics in Ocean Trawl and Fish Gut Matrices [J]. Analytical Methods, 2016, 9(9): 1479-1490. [62] AVIO C G, GORBI S, REGOLI F. Experimental development of a new protocol for extraction and characterization of microplastics in fish tissues: First observations in commercial species from Adriatic Sea [J]. Marine Environmental Research, 2015, 111: 18-26. doi: 10.1016/j.marenvres.2015.06.014 [63] HURLEY R R, LUSHER A L, OLSEN M, et al. Validation of a method for extracting microplastics from complex, organic-rich, environmental matrices [J]. Environmental Science & Technology, 2018, 52(13): 7409-7417. [64] LÖDER M G J, GERDTS G. Methodology Used for the detection and identification of microplastics—A critical appraisal[B]. Springer, Cham, 2015: 201-227. https://doi.org/10.1007/978-3-319-16510-3_8 [65] FELSING S, KOCHLEUS C, BUCHINGER S, et al. A new approach in separating microplastics from environmental samples based on their electrostatic behavior [J]. Environmental Pollution, 2018, 234: 20-28. doi: 10.1016/j.envpol.2017.11.013 [66] GRBIC J, NGUYEN B, GUO E, et al. Magnetic extraction of microplastics from environmental samples [J]. Environmental Science & Technology Letters, 2019, 6(2): 68-72. [67] 王昆, 林坤德, 袁东星. 环境样品中微塑料的分析方法研究进展 [J]. 环境化学, 2017, 36(1): 27-36. doi: 10.7524/j.issn.0254-6108.2017.01.2016051704 WANG K, LIN K D, YUAN D X. Research progress on the analysis of microplastics in the environment [J]. Environmental Chemistry, 2017, 36(1): 27-36(in Chinese). doi: 10.7524/j.issn.0254-6108.2017.01.2016051704
[68] MILLER M E, KROON F J, MOTTI C A. Recovering microplastics from marine samples: A review of current practices [J]. Marine Pollution Bulletin, 2017, 123(1/2): 6-18. [69] DEVRIESE L I, VAN D M, MYRA D, et al. Microplastic contamination in brown shrimp (Crangon crangon, Linnaeus 1758) from coastal waters of the Southern North Sea and Channel area [J]. Marine Pollution Bulletin, 2015, 98(1/2): 179-187. [70] LUSHER A, WELDEN N, SOBRAL P, et al. Sampling, isolating and identifying microplastics ingested by fish and invertebrates [J]. Analytical Methods, 2016, 9(9): 1346-1360.