AOAC ERP Fertilizers - March 2019

3/14/2019

AOAC EXPERT REVIEW PANEL FOR FERTILIZERS

UPDATE ON ADDITIONAL VALIDATIONS AND NEXT STEPS FOR THE METHOD  • Method “updates” – Nebulizer change • OptiMist XL® Nebulizer  • Why: • Virtually unclog‐able • Reduces need for sample filtering • Sample channel is > 1.0 mm • Introduction or pump tubing will clog first

Sample Orifice

Sample Channel

Gas Orifice

• Relatively Inexpensive • Extended life (1‐2 yrs) • Non‐concentric nebulizer

Gas Channel

• May be a slight loss in RSD precision & MDL versus a  concentric, but not likely a problem for high P/K fertilizers • With P, want to minimize introduction of aerosol into the  plasma  (i.e. high Carbon and ionization requirement)  so  set pump rpm just above aerosol pulsation 

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AOAC EXPERT REVIEW PANEL FOR FERTILIZERS

UPDATE ON ADDITIONAL VALIDATIONS AND NEXT STEPS FOR THE METHOD  • If still need low MDLs and RSDs, there is  another non‐concentric option, but it  has a higher clogging potential. • OptiMist Vortex®  • Has “striker plate” • Requires a different spray chamber

• TSP contact info:

Texas Scientific Products, LLC 11941 Hilltop Road, Suite 15 Argyle, TX 76226 Main Number: 888‐268‐6037 www.txscientific.com

Data is courtesy of University of KY, Division of Regulatory Services Fertilizer Program  

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