The preparation of accurate and stable OP standards is complicated by their sensitivity to light, pH, heat, and water. Restek has spent more than four years researching OP pesticide mixtures. Our research results:

• OP standards have a maximum of 12 months shelf life due to their volatility. It is our policy to ship standards with no less than 3 months shelf life remaining.
• Solvents are assayed to ensure low water content.
• Reference mixtures are stored in deactivated amber ampules, under an inert atmosphere.
• Purity is determined by a combination of methods: GC/FID, GC/FPD, GC/NPD, DSC, and HPLC/UV.

FPD Detector:
Internal Standard: none recommended
Surrogate: tributylphosphate (cat.# 32280) and triphenylphosphate (cat.# 32281)