spICP-MS characterisation of released silver nanoparticles from (nano)textile products

The low limits of detection and information regarding the concentration and size distribution of nanoparticles provided by single particle inductively coupled plasma mass spectrometry (spICP-MS) has been taken in advance for assessing released silver nanoparticles from (nano)textiles (nanosilver textiles). The releasing procedure consisted of using orbital-horizontal shaking (100 rpm, 20 °C, 30 min) and ultrapure water (10 mL) as an extractant, and it was found to guarantee silver nanoparticles stability (silver nanoparticle concentration and size distribution). Stability of released silver nanoparticles was further investigated at several filtration (0.22, 0.45 and 5.0 μm) and centrifugation conditions, stages required for fluff removal after extraction and just before spICP-MS determinations. Filtration using 5.0 μm filters was found to not affect silver nanoparticles concentrations and size distributions. The extractive procedure plus spICP-MS has shown a limit of detection and a limit of quantification for silver nanoparticle number concentration of 4.59 × 104 and 1.53 × 105 silver nanoparticles per gram of textile, respectively, whereas a limit of detection in size of 12 nm was obtained. Repeatability of the overall procedure was 14% (silver nanoparticle concentration) and 6% (mean silver nanoparticle size). Similarly, analytical recovery assays using standard silver nanoparticles of 20, 40, and 60 nm led to recoveries within the 102–113% range. The high degree of fixation of the AgNPs to the fabric and the softness of the extraction process to guarantee the integrity of the nanoparticles has led to a non-quantitative extraction (extraction percentages between 0.3 and 9.0% depending on the textile sample). However, the methodology developed has proven to be highly efficient for the characterization of the extracted AgNPs, and robust since the stability of the released AgNPs during the extraction procedure.