The Application Notebook
Glyphosate is a broad-spectrum herbicide widely used around the world. Monitoring of glyphosate in crops and water is mandated in many countries.
Glyphosate is a broad-spectrum herbicide widely used around the world. Monitoring of glyphosate in crops and water is mandated in many countries. We describe a sensitive and robust HPLC method for analysis of glyphosate in soy beans, corn, and sunflower seeds. This method utilizes a simplified sample preparation procedure that has proven to be effective even for challenging matrices.
Supplies for Sample Preparation
Methylene Chloride, HPLC Grade
Acidic Modifier Solution (16 g KH2PO4, 160 mL of water, 40 ml of Methanol, 13.4 mL of conc. HCl)
Elution Solution (160 mL of water, 40 mL of Methanol, 2.7 mL of HCl)
RESTORE™
Table I: HPLC Gradient
SPE sample clean-up cartridges P/N 1705-0001
Sample Preparation
Extraction
To 25 g of homogenized sample, add enough water (after estimating moisture content) such that the total volume of water is 125 mL. Blend at high speed for 3–5 min and centrifuge for 10 min. Transfer 20 mL of the aqueous extract into a centrifuge tube and add 15 mL of methylene chloride. Shake for 2–3 min and centrifuge for 10 min. Transfer 4.5 mL of aqueous layer to another centrifuge tube and add 0.5 mL of acidic modifier solution. Shake and centrifuge for 10 min. Filter through a 0.45 μm filter.
Table II: Recoveries for Glyphosate
Matrix-Specific Modifications
Matrix with high 1) Water; 2) Protein; 3) Fat Content:
1) For samples that absorb large amounts of water, reduce test portion to 12.5 g while keeping water volume the same.
2) For samples with high protein content, add 100 μL of concentrated HCl to 20 mL of crude extract. Shake and centrifuge for 10 min.
Figure 1: Chromatogram of soy beans sample spiked with Glyphosate at 0.1 ppb level.
3) For samples with high fat content, do the methylene chloride partitioning twice.
SPE Cleanup
Remove the top cap first, then the bottom cap of the SPE columns and place them into the manifold. Drain the solution to the top of the resin bed. Transfer 1 mL of extract into the column and elute to the top of the resin bed. Add 0.7 mL of the elution solution and discard the effluent. Repeat with a second 0.7 mL portion of the elution solution and discard the effluent. Elute glyphosate with 12 mL of the elution solution and collect the effluent in a round bottom flask. Evaporate to dryness at 40 °C using a rotary evaporator. Dissolve the residue in 2.0 mL of a solution of 10% RESTORE™ in water (use 1.5 mL for dry samples), filter through a 0.45 μm syringe filter and inject onto the HPLC column. Extracts can be stored refrigerated for up to seven days before the evaporation step.
Figure 2: Chromatogram of corn sample spiked with Glyphosate at 0.1 ppb level.
Figure 3: Chromatogram of sunflower seeds sample spiked with Glyphosate at 0.1 ppb level.
Pickering Laboratories
1280 Space Park Way, Mountain View, CA 94043
tel. (800) 654-3330, fax (408) 694-6700
Website: www.pickeringlabs.com
AI and GenAI Applications to Help Optimize Purification and Yield of Antibodies From Plasma
October 31st 2024Deriving antibodies from plasma products involves several steps, typically starting from the collection of plasma and ending with the purification of the desired antibodies. These are: plasma collection; plasma pooling; fractionation; antibody purification; concentration and formulation; quality control; and packaging and storage. This process results in a purified antibody product that can be used for therapeutic purposes, diagnostic tests, or research. Each step is critical to ensure the safety, efficacy, and quality of the final product. Applications of AI/GenAI in many of these steps can significantly help in the optimization of purification and yield of the desired antibodies. Some specific use-cases are: selecting and optimizing plasma units for optimized plasma pooling; GenAI solution for enterprise search on internal knowledge portal; analysing and optimizing production batch profitability, inventory, yields; monitoring production batch key performance indicators for outlier identification; monitoring production equipment to predict maintenance events; and reducing quality control laboratory testing turnaround time.
2024 EAS Awardees Showcase Innovative Research in Analytical Science
November 20th 2024Scientists from the Massachusetts Institute of Technology, the University of Washington, and other leading institutions took the stage at the Eastern Analytical Symposium to accept awards and share insights into their research.