Appendix D: Analytical Methods 



Note: Working solutions from the stock reference solutions should be prepared on a regular basis 

 and stored in clean glass vials tightly capped with non-contaminating materials such as teflon or 

 glass. Extreme care must be taken to ensure that standards have not changed their concentrations 

 through solvent evaporation. This can be done efficiently by weighing solutions on an electronic 

 balance with the weight recorded on the vial. 



3.3 Apparatus 



a. High purity carrier gas for the gas chromatograph including molecular traps to remove trace 

 contaminants and moisture. 



b. Rotary evaporator. 



c. Kudema-Danish (or similar) concentrator and heater. 



d. Soxhlet and/or tissue miser (e.g., Bransonic). 



e. Glassware including boiling flasks, ground glass stoppers, beakers, Erlenmeyer flasks, 

 gas chromatography columns (length 1.8 m, 0.4 cm I. D.), separatory funnels, centrifuge 

 tubes, weighing bottles, pipettes, syringes, tissue grinders. 



f . Drying oven (temperature range up to at least 300°C) for determining sample dry weights, 

 baking of contaminant residues from glassware and reagents. 



A muffle furnace is required for baking materials, such as Na2SC>4, at greater than 300°C, if 

 required. 



g. Centrifuge and tubes (at least 600 x g). 



h . Porcelain mortar and pestle. 



i. Analytical balance with a precision of 0.0001 g and an electrobalance with a precision of at 

 least 1 (ig. 



j. Stainless steel tweezers and spatulas. 



k. Glass wool. 



1. Supply of clean, dry nitrogen. 



87 



