Table 9.
Recovery data for spiked negative controls: Minor ephedrine alkaloids
| Average amounts, μg/g | ||||
|---|---|---|---|---|
| Samplea | Negative control | Low spike | High spike | |
| NE | Amount added | 0 | 114 | 1450 |
| Amount found | 0 | 72.3 | 563 | |
| Recovery, % | NAb | 63.4 | 38.8 | |
| NP | Amount added | 0 | 103 | 614 |
| Amount found | c | 366 | 964 | |
| Recovery, % | NA | 356 | 157 | |
| ME | Amount added | 0 | 316 | 4990 |
| Amount found | 0 | 200 | 2580 | |
| Recovery, % | NA | 63.3 | 51.7 | |
| MP | Amount added | 0 | 95.4 | 1360 |
| Amount found | 0 | 67.0 | 727 | |
| Recovery, % | NA | 70.2 | 53.5 | |
a
NE = Norephedrine; NP = norpseudoephedrine; ME = methylephedrine; MP = methylpseudoephedrine.
b
NA = Not applicable.
c
Laboratories A and B reported results for NP in this sample.