I ordered a Napa oil analysis kit today and plan on sending off a sample of my SJ Kendall GT-1 High Performance SAE 30. The sample I'm wanting tested is poured in a 1 quart glass jar, which was clean and sealed upon opening it. My question is do I need to just sample some out of a sealed quart bottle to eliminate the possibility of contaminants? The jar was never previously used and I purchased it new. The jar has only been exposed to the light of my bedside lamp. The jar is holding just over a quart also, so am I going to have a higher concentration of additives from the oil being a quart and a half mixed? I'm thinking no, because how could that be any different than sampling from a 5 qt container? Thank you.