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

Figure 2

Comparison of peak intensities based on the PHMG standard solution of each product. Types A, B, and C indicate the linear structure, whereas types D and E indicate the branched and cyclic structure, respectively (Figure S4). There were relatively more E structures than D structures in Oxy product (d), and there was no D structure in Scunder product (h) and BOC product (l). STD1: 1 ppm; STD 2: 5 ppm; STD 3: 10 ppm; STD 4: 50 ppm; STD 5: 100 ppm.

(a) Oxy product: type A

(b) Oxy product: type B

(c) Oxy product: type C

(d) Oxy product: types D and E

(e) Scunder product: type A

(f) Scunder product: type B

(g) Scunder product: type C CCA

(h) Scunder product: type E

(i) BOC product: type A

(j) BOC product: type B

(k) BOC product: type C

(l) BOC product: type E