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ENVIRONMENTAL ANALYSIS I. Solid Phase Extraction. step-by-step method development. Goal of Six-Step Mode. Isolation Purification Trace enrichment. Six-Step Method Development. Compile known parameters Tech Support Form Follow step-by-step guide Fill in method development form.
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ENVIRONMENTALANALYSISI. Solid Phase Extraction step-by-step method development
Goal of Six-Step Mode • Isolation • Purification • Trace enrichment
Six-Step Method Development • Compile known parameters • Tech Support Form • Follow step-by-step guide • Fill in method development form
Pertinent Data • The analyte(s) • The matrix • The analytical method • Existing method(s)
The Analyte • Structure • pKa(s) • Concentration • Sample volume • Solubility • Stability
The Matrix • Type of matrix • pH and ionic strength • Interferences
The Analytical Method • Final technique • Compatible solvents • HPLC conditions
Existing Method • Liquid-liquid method • Current SPE method details • Data from current method
Dr. Anna Light Pollution Unlimited 1224 Sunnyside Drive Elution, Alaska (907) 663-3217 573 (907) 663-3218 Method Development Example
The “Form” Sample name _________________ Analyte of Interest ________________ Sample size ____________________ Sorbent Bed Mass _______ Cartridge volume_____ Sorbent phases to try 1) _____ 2) _____ 3) _____ 4) _____ 1. Sample pretreatment ___________________________ 2. Condition column with ____ mL of _________ at ___ mL/min 3. Equilibrate column with ____ mL of _________ at ___ mL/min. 4. Load sample at ______ mL per minute. 5. Remove interference with ____ mL of _________ at ___ L/min. Drying step _____ minutes 6. Elute analyte with ____ mL of _________ at ___ mL/min. Remember to include soak step if possible!
Sorbent Capacity Hydrophobic phases: 1- 5% of Sorbent Mass Ion Exchangers 0.3 to 0.6 milli-equivalents per gram