Table 8.
Amino acid testing results, blank corrected. For these experiments the samples were split, with half analyzed without hydrolysis (free amino acids) and the other half acid-hydrolyzed, according to Glavin et al. (2006), to show both free amino acids and those bound (presumably as peptides in this case). Bags were extracted in water and reported as concentration in solution
| Sample | Free amino acids (ng/cm2) | Total amino acids (ng/cm2) |
|---|---|---|
| Uncleaned screw | 14.91 | 89.64 |
| Dirtied screw | 54.58 | 252.01 |
| Dirtied and cleaned | 0.50 | 1.97 |
| Nylon packaged | 13.69 | 101.13 |
| Nylon packaged and cleaned | 0.50 | 1.50 |
| Kimberly Clark 55082 medium purple nitrile glove used at GSFC | n.d. | 67.3 ng/g |
| Kimtech G3 medium tan nitrile gloves used at LM | n.d. | 646.2 ng/g |
| TechNitrile medium blue nitrile gloves | n.d. | 150.3 ng/g |
| Dry Kimtech glove rubbed on foil | n.d. | 0.97 |
| Fisher Optima 2-propanol wet Kimtech glove rubbed on foil | n.d. | 0.13 |
| Nylon (KNF LB106) | n.d. | 38,000 ng/g |
| PFTE (KNF LB605) | n.d. | 17 ng/g |
| Polypropylene (KNF LB3022) | n.d. | 7.8 ng/g |
| Tyvek® (Beacon Converters A7373) | n.d. | 6.3 ng/g |
| Lamellar polypropylene (KNF Kenlam 7150) | n.d. | 1.4 ng/g |
| Lamellar polyethylene (Beacon Converters FR2176) | n.d. | 0.060 ng/g |
| Aluminum (Reynolds extra heavy duty foil hot bag) | n.d. | 0.015 ng/g |
| 2-Propanol (Fisher ACS) | n.d. | <0.05 ng/g |
| 2-Propanol (Fisher Optima) | n.d. | <0.05 ng/g |
n.d. = not determined