## 6 Methods of Microplastics Analysis
### The Evaluation of Analysis Methods  
The main analytical technique used now is vibrational spectroscopy, which does not harm the sample and may reveal the physical and chemical properties of MPs. Additionally, widely analyzed MPs from water and soil mostly involve FTIR and Raman methods of vibrational spectroscopy. Research on airborne MPs has slowly begun to surface in recent years, but most of the work that has been published so far has concentrated on atmospheric deposition and a particular topic. Additionally, the fluorescence background can readily \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Method** & **Particle Size** & **Advantages** & **Limitations** \\ \hline Scanning ElectronSpectroscopy & Analysis is possible for particles with diameters as small as a micron. & Creates a high-resolution picture of the samples. & High vacuum is required to cover the samples, and there is no precise identification data available. \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\ \end{tabular}
\end{table} 
Table 5: The most popular methods for analyzing microplastics: advantages and limitations. affect Raman, which slows down its development. High spectral noise, spatial resolution, and a poor ability to identify water-containing materials are all characteristics of FTIR. Due to the destructive nature of the thermal analytical method's identification process, it is impossible to determine the quantity and shape of MPs. The main drawback of Pyr-GC-MS is that the sample mass is just 0.5 mg and MPs must be manually inserted in the pyrolysis reaction tube. To fully detect MPs, it is necessary to create a spectrum database of popular plastic types. TED-GC-MS improves the sample mass to 100 mg and overcomes the limitation of sample contamination from the reaction tube. However, high temperature, which can reach 1000 \({}^{\circ}\)C, hinders its development. DSC has a promising future in the analysis of MPs in water. However, this approach needs pretreatment and only effectively detects MPs of the type of PE and PP. In conclusion, the thermal analytical method's reaction temperature is high, and the leakage of MPs' combustion products contributes to environmental pollution. Terahertz spectroscopy (THz) offers the qualities of solid penetration and high sensitivity, but the equipment is expensive and heavy, plus the spectrum signal-to-noise ratio is poor. High spectrometry imaging (HSI), whose images contain hundreds of small spectral bands from visible light to infrared and tens of thousands of pixel space, can directly offer samples of visual effects. As a result, we can swiftly determine the chemical make-up of MPs including other details like size, shape, and so forth, according to each pixel space. This technique offers a fresh approach to detecting MP pollution. However, this method's quick advancement is slowed down by difficult operation procedures and poor image quality. In addition, the machine learning technique for detecting MPs in conjunction with the spectrum analysis technique is still under development. Both HPLC and SEM-EDS are rarely utilized for MPs identification. Currently, SEM-EDS is mostly utilized to identify NPs. However, this approach does not offer information about the chemical composition of plastics. Additionally, HPLC may be modified to analyze huge samples. The chemical makeup of samples can theoretically be discovered. Currently, SEM-EDS have been used to identify PA, PS, PE, PP, and PVC in nature. Only their absorption content and amount have been determined. SEM-EDS must therefore be developed further. The Raman spectrum's fluorescence background interference must be eliminated. Modern unconventional Raman spectroscopy techniques including face-off and nonlinear Raman spectroscopy can increase spectral data signal-to-noise ratios as well as Raman intensity. The increase in signal strength brought forth by nonlinearity, such as CARS and SRS, creates a new avenue for the investigation of MPs in real time.