| 10913-2 | 4,4'-Methylene bis(2-Chloroaniline) [Mass/volume] in Urine | 4,4'-Methylene bis(2-Chloroaniline) |
| 38746-4 | 4,4'-Methylene bis(2-Chloroaniline) [Mass/volume] in Air | 4,4'-Methylene bis(2-Chloroaniline) |
| 48137-4 | 4,5-Dihydroxyhexanoate/Creatinine [Molecular ratio] in Urine | 4,5-Dihydroxyhexanoate/Creatinine |
| 48106-9 | 4,5-Dihydroxyhexanolactone/Creatinine [Molecular ratio] in Urine | 4,5-Dihydroxyhexanolactone/Creatinine |
| 38690-4 | 4,6-Dinitro-O-Cresol [Mass/volume] in Air | 4,6-Dinitro-O-Cresol |
| 38632-6 | 4-Biphenylamine [Mass/volume] in Air | 4-Biphenylamine |
| 47823-0 | 4-Hydroxy-3-Methoxyphenyllactate/Creatinine [Molecular ratio] in Urine | 4-Hydroxy-3-Methoxyphenyllactate/Creatinine |
| 43732-7 | 4-Hydroxybenzoate [Presence] in Urine | 4-Hydroxybenzoate |
| 43733-5 | 4-Hydroxybenzoate [Presence] in 24 hour Urine | 4-Hydroxybenzoate |
| 47541-8 | 4-Hydroxybenzoate/Creatinine [Molecular ratio] in Urine | 4-Hydroxybenzoate/Creatinine |
| 51189-9 | 4-Hydroxybupivacaine [Mass/volume] in Serum or Plasma | 4-Hydroxybupivacaine |
| 29869-5 | 4-Hydroxycyclohexylacetate [Presence] in Urine | 4-Hydroxycyclohexylacetate |
| 13544-2 | 4-Hydroxyglutethimide [Presence] in Serum or Plasma | 4-Hydroxyglutethimide |
| 35637-8 | 4-Hydroxyglutethimide [Mass/volume] in Serum or Plasma by Screen method | 4-Hydroxyglutethimide |
| 50293-0 | 4-Hydroxyifosfamide [Mass/volume] in Blood --1 day post dose ifosfamide | 4-Hydroxyifosfamide^1D post dose ifosfamide |
| 50294-8 | 4-Hydroxyifosfamide [Mass/volume] in Blood --2 days post dose ifosfamide | 4-Hydroxyifosfamide^2D post dose ifosfamide |
| 50295-5 | 4-Hydroxyifosfamide [Mass/volume] in Blood --3 days post dose ifosfamide | 4-Hydroxyifosfamide^3D post dose ifosfamide |
| 50298-9 | 4-Hydroxyifosfamide [Mass/volume] in Blood --3 hours post dose ifosfamide | 4-Hydroxyifosfamide^3H post dose ifosfamide |
| 50296-3 | 4-Hydroxyifosfamide [Mass/volume] in Blood --4D post dose ifosfamide | 4-Hydroxyifosfamide^4D post dose ifosfamide |
| 50297-1 | 4-Hydroxyifosfamide [Mass/volume] in Blood --5 days post dose ifosfamide | 4-Hydroxyifosfamide^5D post dose ifosfamide |
| 50299-7 | 4-Hydroxyifosfamide [Mass/volume] in Blood --6 hours post dose ifosfamide | 4-Hydroxyifosfamide^6H post dose ifosfamide |
| 50292-2 | 4-Hydroxyifosfamide [Mass/volume] in Blood --pre dose ifosfamide | 4-Hydroxyifosfamide^pre dose ifosfamide |
| 44861-3 | 4-Hydroxymandelate/Creatinine [Mass ratio] in Urine | 4-Hydroxymandelate/Creatinine |
| 47543-4 | 4-Hydroxymandelate/Creatinine [Molecular ratio] in Urine | 4-Hydroxymandelate/Creatinine |
| 27270-8 | 4-Hydroxyphenylacetate [Presence] in Urine | 4-Hydroxyphenylacetate |
| 13696-0 | 4-Hydroxyphenylacetate/Creatinine [Mass ratio] in Urine | 4-Hydroxyphenylacetate/Creatinine |
| 25088-6 | 4-Hydroxyphenylacetate/Creatinine [Molecular ratio] in Urine | 4-Hydroxyphenylacetate/Creatinine |
| 28585-8 | 4-Hydroxyphenylacetate/Creatinine [Ratio] in Urine | 4-Hydroxyphenylacetate/Creatinine |
| 29870-3 | 4-Hydroxyphenyllactate [Presence] in Urine | 4-Hydroxyphenyllactate |
| 13697-8 | 4-Hydroxyphenyllactate/Creatinine [Mass ratio] in Urine | 4-Hydroxyphenyllactate/Creatinine |
| 25089-4 | 4-Hydroxyphenyllactate/Creatinine [Molecular ratio] in Urine | 4-Hydroxyphenyllactate/Creatinine |
| 28586-6 | 4-Hydroxyphenyllactate/Creatinine [Ratio] in Urine | 4-Hydroxyphenyllactate/Creatinine |
| 29871-1 | 4-Hydroxyphenylpyruvate [Presence] in Urine | 4-Hydroxyphenylpyruvate |
| 13698-6 | 4-Hydroxyphenylpyruvate/Creatinine [Mass ratio] in Urine | 4-Hydroxyphenylpyruvate/Creatinine |
| 29519-6 | 4-Hydroxyphenylpyruvate/Creatinine [Molecular ratio] in Urine | 4-Hydroxyphenylpyruvate/Creatinine |
| 1688-1 | 4-Pyridoxate [Mass/volume] in Serum or Plasma | 4-Pyridoxate |
| 35586-7 | 4-Tert-Butylphenol [Mass/volume] in Urine | 4-Tert-Butylphenol |
| 42059-6 | None | 4th course treatment.biological response modifier therapy |
| 42057-0 | None | 4th course treatment.chemotherapy |
| 42058-8 | None | 4th course treatment.hormonal therapy |
| 42060-4 | None | 4th course treatment.other therapy |
| 42056-2 | None | 4th course treatment.radiation |
| 42055-4 | None | 4th course treatment.surgery |