Table IIb.
Method validation for phthalates: intra- and inter-assay controls and recoveries
| Intra-assay | Recovery | Inter-assay | ||||||
|---|---|---|---|---|---|---|---|---|
| Mean | SD | CV (%) | Mean (%) | Mean | SD | CV (%) | ||
| 50 ng/mL | 500 ng/mL | |||||||
| MMP | ||||||||
| Medium | 7.50 | 0.6 | 8 | 105 | 97 | 6.00 | 0.6 | 10 |
| High | 48.3 | 2.7 | 6 | 101 | 94 | 44.4 | 2.9 | 7 |
| MEP | ||||||||
| Low | 150 | 3.9 | 3 | 113 | 93 | 151 | 14 | 9 |
| High | 208 | 5.6 | 3 | 94 | 86 | 196 | 13 | 7 |
| MiBP | ||||||||
| Low | 34.4 | 1.9 | 6 | 103 | 101 | 29.0 | 1.8 | 6 |
| High | 167 | 7.9 | 5 | 115 | 96 | 152 | 19 | 12 |
| MnBP | ||||||||
| Low | 27.7 | 1.2 | 4 | 111 | 102 | 27.4 | 1.7 | 6 |
| High | 161 | 3.4 | 2 | 115 | 88 | 164 | 7.1 | 4 |
| MnHP | ||||||||
| Low | 4.80 | 0.2 | 4 | 105 | 95 | 4.80 | 0.2 | 4 |
| High | 46.1 | 1.0 | 2 | 104 | 93 | 45.0 | 2.0 | 5 |
| MEHP | ||||||||
| Low | 10.7 | 0.7 | 7 | 103 | 95 | 11.1 | 0.7 | 7 |
| High | 52.1 | 2.1 | 4 | 99 | 94 | 53.8 | 2.2 | 4 |
| MEHHP | ||||||||
| Low | 16.0 | 0.4 | 2 | 99 | 102 | 15.3 | 1.1 | 7 |
| High | 113 | 2.2 | 2 | 104 | 97 | 111 | 4.6 | 4 |
| MEOHP | ||||||||
| Low | 13.6 | 0.3 | 3 | 104 | 96 | 13.8 | 0.7 | 5 |
| High | 107 | 4.0 | 4 | 113 | 96 | 109 | 5.0 | 5 |
| MECPP | ||||||||
| Low | 17.9 | 0.7 | 4 | 103 | 99 | 18.0 | 1.1 | 6 |
| High | 116 | 3.0 | 3 | 105 | 97 | 119 | 7.6 | 6 |
| MBzP | ||||||||
| Low | 10.6 | 1.1 | 10 | 99 | 100 | 10.8 | 0.7 | 6 |
| High | 91.7 | 8.4 | 9 | 93 | 100 | 88.5 | 5.9 | 7 |
| MiNP | ||||||||
| Low | 5.50 | 0.2 | 3 | 111 | 92 | 5.30 | 0.2 | 4 |
| High | 54.7 | 1.7 | 3 | 100 | 89 | 54.6 | 2.0 | 4 |
| MHiNP | ||||||||
| Low | ND | ND | ND | |||||
| High | ND | ND | ND | |||||
| MiDP | ||||||||
| Low | 4.50 | 0.2 | 4 | 110 | 98 | 4.60 | 0.3 | 7 |
| High | 45.5 | 2.0 | 4 | 106 | 97 | 50.4 | 3.8 | 8 |
Names and abbreviations of all analytes are shown in Table I. SD, standard deviation; CV, coefficient of variability; ND, not determined.