Connect the USB drive or pen drive to your computer and launch EaseUS USB data recovery software on your PC. Select the drive which is labeled as a External drives, and click \"Scan\" to start looking for lost files.
After the process, you can check your USB drive and use it for file transfers to see the changes. If this method doesn't work well, you can format your USB. Do remember to back up your USB to avoid unnecessary data loss.
In order to better assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that can determine sorbed organic contaminants. An important step is the extraction of the chemicals from the plastic matrices, which can present heterogeneous physical-chemical characteristics depending on the polymer type, its degradation stage, and pre-treatments. Most of the investigations reported in the literature use maceration or Soxhlet techniques4,5,6,9,13,14,15,16,17,18, which are solvent and/or time consuming. Regarding the growing interest for this issue, alternatives should be developed, for a faster evaluation of organic contaminants adsorbed on plastic pieces. In addition, plastic chemical analysis provides information about the chemical structure of the microplastics. As a result, the predominant types of polymers and copolymers present in the environment can be evaluated. Although plastic fragments are usually made of polyethylene (PE) and polypropylene (PP)5, some sampling locations can present a particular profile where other categories are significantly represented (e.g., ethylene/vinyl acetate copolymer and polystyrene (PS)). FT-IR spectroscopy is a reliable and user-friendly technique for polymer identification commonly used to identify microplastics19,20.
Whitish and yellowish pellets are usually predominant over other pellets, especially pigmented ones. However, some sampling sites present a particular profile and therefore it is advised to classify the plastic pieces by color (visual assessment) prior to extraction. A visual reference can be created to help sorting the pellets as presented onFigure 2(from left to right: white/transparent, whitish/yellowish, yellow/orange, amber/brown, and pigmented).
In many studies4,8,13,16,18, only aged PE pellets are analyzed for their adsorbed organic contaminant content. Because of their surface properties, this category of polymers has a greater affinity to adsorb environmental pollutants than other type of pellets and they are the predominant polymer class4. However, some sampling locations present a special profile with an abundance of less aged pellets (i.e., white or transparent) and/or a higher variety in polymer types than commonly found. Thus, a different approach is suggested here to avoid a possible overestimation of the organic contaminant levels. The classification of plastic pellets is based on color rather than on polymer type. Moreover, the identification of the plastic type can still be carried out after the extraction step. By proceeding in this order, the risk of sample contamination during the polymer chemical analysis is lowered and the plastic identification process can be facilitated by cutting the pellets, as previously explained. Extracting organic contaminants from items that are mistaken for plastic pellets would be the main limitation of this methodology. However, it can be underlined that only a negligible fraction (i.e., less than 0.5%) of the sampled pellets is shown not to be made of plastic polymer after chemical analysis. 59ce067264