Sample preparation and extraction of steroids is by either liquid-liquid extraction (LLE) or supported liquid extraction (SLE) followed by an on-line 2D polishing extraction. Target steroid analytes are chromatographically separated on a reverse-phase (RP) column. All analytes and Internal Standards are measured by ESI ionization--pos and/or neg polarity (analyte dependent). Creative Proteomics provide customer-tailored service with rapid peptide steroids analysis procedures and easy to read report, to speed up your scientific research. https://www.creative-proteomics.com/services/steroids-analysis-service.htm