(a) 1H NMR spectrum of AV-1. Notice the presence of benzoate (not listed in the product label) and methanol (toxic contaminant) characteristic peaks in this preparation
(b) 1H NMR spectrum of AV-2. Notice the presence of benzoate (not listed in the product label) and methanol (toxic contaminant) characteristic peaks in this preparation as shown in Figure 6(a)
(c) 1H NMR spectrum of AV-3. Notice the presence of benzoate (not listed in the product label) and absence of methanol from characteristic peaks described in Figure 6(a)
(d) 1H NMR spectrum of AV-4. Notice the prominent presence of benzoate listed in the product label and absence of methanol from characteristic peaks described in Figure 6(a)
Figure 6