Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy; Center for Instrument Sharing of the University of Pisa (CISUP), 56126 Pisa, Italy.
Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy.
Sci Total Environ. 2023 Dec 1;902:166043. doi: 10.1016/j.scitotenv.2023.166043. Epub 2023 Aug 5.
Different marine sponge species from Tethys Bay, Antarctica, were analyzed for contamination by polyester and polyamide microplastics (MPs). The PISA (Polymer Identification and Specific Analysis) procedure was adopted as it provides, through depolymerization and HPLC analysis, highly sensitive mass-based quantitative data. The study focused on three analytes resulting from the hydrolytic depolymerization of polyesters and polyamides: terephthalic acid (TPA), 6-aminohexanoic acid (AHA), and 1-6-hexanediamine (HMDA). TPA is a comonomer found in the polyesters poly(ethylene terephthalate) (PET) and poly(butylene adipate co terephthalate) (PBAT), and in polyamides such as poly(1,4-p-phenylene terephthalamide) (Kevlar™ and Twaron™ fibers) and poly(hexamethylene terephthalamide) (nylon 6 T). AHA is the monomer of nylon 6. HMDA is a comonomer of the aliphatic nylon 6,6 (HMDA-co-adipic acid) and of semi-aromatic polyamides such as, again, nylon 6 T (HMDA-co-TPA). Except for the biodegradable PBAT, these polymers exhibit high to extreme mechanical, thermal and chemical resistance. Indeed, they are used as technofibers in protective clothing able to withstand extreme conditions as those typical of Antarctica. Of the two amine monomers, only HMDA was found above the limit of quantification, and only in specimens of Haliclona (Rhizoniera) scotti, at a concentration equivalent to 27 μg/kg of nylon 6,6 in the fresh sponge. Comparatively higher concentrations, corresponding to 2.5-4.1 mg/kg of either PBAT or PPTA, were calculated from the concentration of TPA detected in all sponge species. Unexpectedly, TPA did not originate from PET (the most common textile fiber) as it was detected in the acid hydrolysate, whereas the PISA procedure results in effective PET depolymerization only under alkaline conditions. The obtained results showed that sponges, by capturing and concentrating MPs from large volumes of filtered marine waters, may be considered as effective indicators of the level and type of pollution by MPs and provide early warnings of increasing levels of pollution even in remote areas.
从南极洲 Tethys 湾的不同海洋海绵物种中分析了聚酯和聚酰胺微塑料 (MPs) 的污染情况。采用 PISA（聚合物识别和特定分析）程序，通过解聚和 HPLC 分析提供了高度敏感的基于质量的定量数据。该研究集中于三种分析物，它们是聚酯和聚酰胺水解解聚的产物：对苯二甲酸 (TPA)、6-氨基己酸 (AHA) 和 1-6-己二胺 (HMDA)。TPA 是聚对苯二甲酸乙二醇酯 (PET) 和聚丁二酸丁二醇酯共对苯二甲酸酯 (PBAT) 等聚酯以及聚酰胺如聚 (1,4-对苯二甲酰苯二胺) (Kevlar™ 和 Twaron™ 纤维) 和聚 (六亚甲基对苯二甲酰胺) (尼龙 6 T) 中的共聚单体。AHA 是尼龙 6 的单体。HMDA 是脂肪族尼龙 6,6（HMDA-己二酸）和半芳香族聚酰胺（如尼龙 6 T）的共聚单体。除了可生物降解的 PBAT 外，这些聚合物表现出高到极高的机械、热和化学稳定性。事实上，它们被用作防护服中的技术纤维，能够承受类似于南极洲的极端条件。在这两种胺单体中，只有 HMDA 被发现超过了定量限，而且仅在 Haliclona (Rhizoniera) scotti 的标本中被发现，浓度相当于新鲜海绵中尼龙 6,6 的 27μg/kg。从所有海绵物种中检测到的 TPA 浓度计算出相对较高的浓度，相当于 PBAT 或 PPTA 的 2.5-4.1mg/kg。出乎意料的是，TPA 并非源自 PET（最常见的纺织纤维），因为它在酸水解物中被检测到，而 PISA 程序仅在碱性条件下才能有效地使 PET 解聚。研究结果表明，海绵通过从大量过滤海水中捕获和浓缩 MPs，可以被视为 MPs 污染水平和类型的有效指标，并提供即使在偏远地区污染水平不断上升的早期预警。
