Characterization of Polyhexamethylene Guanidine Oligomers in Solutions and Aerosols Emitted during Humidifier Use

Figure 1

Chromatogram of three PHMG products based on standard solution (100 ppm). Types A, B, and C have a linear structure, whereas types D and E have a branched or cyclic structure. The cyclic F structure was not detected. The numbers after the type letter indicate the monomer unit; for example, A2 stands for the linear structure (Figure S4) with two monomer units (dimer).

(a) Oxy product

(b) Scunder product

(c) BOC product