Are there methods available for minimizing the potential interferences?

Answer Explanations

• Yes (please explain)

  Expert 3
  Still probably not standardized, but, for example, tissue-specific protocols could be devised and, in spectroscopic analyses, pre-cleaning of samples with ultrapure water or ethanol could help in removing residual organics. Most importantly, however, would be the constant and repeated use of blanks. 
• Yes (please explain)

  Expert 9
  The best approach I am aware of is to remove as much of the biological matrix giving rise to the interferences as possible - e.g. clean-up methods that oxidise biopolymers but to which MNPs are resistant.
• Yes (please explain)

  Expert 2
  There are several strategies that are reported to be able to minimize the interference from  the biological matrices during microplastic extraction, depending on the tissue type and plastic chemistry. Those consist in  developing optimized digestion  protocols (like  a sequential digestion  using enzymes, mild alkaline or oxidative reactive depending on the type of tissue as well as having a good temperature control adequate for every type of sample), the use of pre-treatment procedures (for example the use of solvent for lipid removal or enzymatic decreasing could reduce inferences that may arise from fatty acids found in some types of tissues and also using EDTA for decalcification for bone tissues could reduce or eliminate the precipitation of plastics), develop protocols for enhance the density separation (this could be achieved by adapting the density of the salt solution  for specific plastics and the use of surfactants in order to reduce the surface tension and prevent aggregation), the use of filtration after the digestion and also a correct rinsing  filters ( it is necessary to use appropriate pore size filters and to rinse them  after each use) as well as using blank controls and recovery tests.
• Yes (please explain)

  Expert 4
  1 - Proper validation of the analytical techniques, as already discussed above and in the previous section 1.
  2 - Selection of the most suited digestion method. Such a method is case dependent and plastic type and matrix composition are important aspects in this respect. Thereupon, it has to be realized that this implies that it is unlikely that there is on forehand a method available that fits all combinations of matrices and plastics. This is an importnat aspect in case of real-world biological tissue samples, either of human or organismal origin.
  3 - Selection of the most suited analytical technique. This depends again on the nature of the tissues and the plastic composition, as well as on the shape and size of the plastics present.
• Yes (please explain)

  Expert 1
  Methods are available and also continue to evolve to minimize or eliminate interferences in MNP analysis.  Biological samples require exhaustive extraction and purification steps.  Currently available methodologies do not have adequate purification steps.  For example, one study showed that after digesting biological matrix with alkali, an ethanol washing step removed significant amount of interferences in pyolysis GCMS analysis of MNPs (Zhou et al. EST 55 (5)).   Alkali digestion can breakdown natural organic matter into smaller fragments that can interfere with MNP analysis, unless those fragments are removed  a washing step with a solvent.  
  
  In addition to purification steps with solvent washing, density separation can help minimize interferences.  
  
  More research is needed to optimize proper sample treatment and analysis.
• Yes (please explain)

  Expert 5
  Careful use of analyte isolation procedures during sample preparation. Match sample processing procedure to  matrix removal and analyte isolation in the biological sample type
• Yes (please explain)

  Expert 6
  There are partial methods to mitigate the potential interferences, including the digestion method discussed in this whitepaper. No one has claimed a universal method to minimizing it successfully.
• Yes (please explain)

  Expert 8
  Increase cleanup.
  For spectroscopy, analyze multiple smaller subsamples to minimize overlap of particles and sum the data across subsamples from the same sample.
  For py-GCMS, a double shot method with an optimized thermal desorption can reduce matrix interference. 
• Yes (please explain)

  Expert 7
  There are established methods to minimize potential interferences from biological matrices, and these methods are tailored to types of tissues, the aimed polymers, and analytical techniques.