We intend to apply this method in our study and would appreciate more detailed procedural information to ensure accurate implementation. Specifically:
– The exact mass of silica gel used for SPE purification per sample and the flow rate or time required during elution?
– The volume and concentration of conditioning and elution solvents for both silica SPE (dust/feces) and HLB SPE (urine)?
– Details on how “near-dry” nitrogen evaporation was achieved—was it visually judged or timed?
– The sample volume or weight-to-solvent ratio used consistently across matrices (e.g., mg sample/mL solvent)?
– The filtration step before GC–MS: was any filter pre-treatment done to prevent analyte loss?
– Injection volume, liner type, and whether splitless or split mode was used in GC–MS?
– Any cleanup or maintenance needed between runs to prevent carryover, especially for complex matrices like feces?
Access to a full procedural document or supplementary file would be very helpful for reproducibility. Thank you!