1：Experimental Design and Method Selection:

The study utilized thermal lens spectrometry (TLS) in both batch mode (BM) and flow injection analysis (FIA) configurations for the determination of colloidal silver in personal care products. The method selection was based on the need for high sensitivity and accuracy in detecting trace levels of colloidal silver.

2：Sample Selection and Data Sources:

Five commercially available personal care products declared to contain nanosilver were examined. Samples included nasal spray, wound disinfection water, nose drops, and water for internal intake.

3：List of Experimental Equipment and Materials:

Equipment included a dual-beam TLS spectrometer, UV-VIS spectrophotometer, ICP-OES spectrometer, and SEM for nanoparticle characterization. Materials included AgNO3, NaBH4, NaOH, and HNO3 for sample preparation and analysis.

4：Experimental Procedures and Operational Workflow:

Samples were analyzed directly for colloidal silver content and after chemical conversion of ionic silver to colloidal form for total silver determination. TLS measurements were performed in batch and FIA modes, with comparative analyses using spectrophotometry and ICP-OES.

5：Data Analysis Methods:

Data were analyzed using calibration curves constructed from standard solutions. Statistical analysis included calculation of LODs, LOQs, and confidence intervals to validate method performance.