TABLE II.
Air-saturated radiolysis tenth scan fractions.a
| pH 5 | pH 7 | pH 9b | ||||
|---|---|---|---|---|---|---|
| Component | Aqueous | 40% Glycerol | Aqueous | 40% Glycerol | Aqueous | 40% Glycerol |
| l-cysteine | 0.73 ± 0.004 | 0.67 ± 0.02 | 0.74 ± 0.02 | 0.72 ± 0.02 | 0.87 ± 0.02 | 0.82 ± 0.03 |
| Cystine | 0.02 ± 0.004 | 0.05 ± 0.003 | 0.09 ± 0.005 | 0.07 ± 0.01 | 0.02 ± 0.01 | 0.07 ± 0.01 |
| Sulfur | 0.19 ± 0.003 | 0.23 ± 0.01 | 0.11 ± 0.004 | 0.17 ± 0.01 | 0.08 ± 0.01 | 0.10 ± 0.01 |
| R3S+ | 0.01 ± 0.001 | 0.02 ± 0.001 | n/a | n/a | … | … |
| Sulfite | 0.01 ± 0.001 | 0.02 ± 0.001 | n/a | nd | … | … |
| Sulfoxide | n/a | n/a | 0.01 ± 0.001 | n/a | … | … |
| Sulfonate | n/a | n/a | n/a | n/a | … | … |
| Sulfate | n/a | n/a | 0.01 ± 0.0003 | n/a | … | … |
a
“nd” is not detected; “n/a” is present but of fraction less than 0.01.
b
For pH 9 solutions, only five scans were recorded, and the fractions for the tenth scan represent extrapolations from linear fits to the data. The extrapolations allow comparison with pH 5 and pH 7 fractions. The pH 9 fifth scan fitted fractions were (aqueous or glycerol) as follows: l-cysteine, 0.95 ± 0.02, 0.92 ± 0.03; cystine, 0.01 ± 0.004, 0.03 ± 0.002; and sulfur, 0.05 ± 0.002, 0.04 ± 0.002. The mean energy deposited per scan was 6.2 × 1017 eV, equivalent to 4 × 105 Gy (sample solution mass = 2.5 × 10−7 kg).