Preparation of a standard method for detection, monitoring and measurements of microplastics with fibre shape

In recent years, an increasing number of microplastics have been found in the environment (air, sediments, freshwaters, rivers and oceans) and a large proportion of them may come from washing effluents of synthetic clothes and show a microfilaments shape. There are no standard method to detection, monitoring and measurements of microplastics. The novelty of the work is the design of a protocol to produce standard suspensions with concentrations between 76 N° filaments/L and 853 N° filaments/L of synthetic microfilaments using four different polymer threads (PA 6, PA 6.6, PET, PP). These were cut at pre-determined lengths of 200 µm and dispersed in three water batches of 300, 500, 900 ml to obtain three different concentrations. The results highlighted the relationship between concentration and probability of the detection of the single microfilaments: increasing the number of microfilaments in the sample suspension the detection probability decreases. Using an appropriate concentration of microfilaments as an internal standard it might be possible to evaluate the recovery rate in microplastics analysis in real sample.