i have used this method to measure fats, but sometimes for samples like honey i do not wash the fat flasks after taking the first constant weight because i dont see any black or insoluble particles in the flask. but the result is too high (like 4.5g/100g, and it should be 0.5g/100g for example). is it possible there could be sugars present in the flask? i extracted carefully with the mojonnier tubes, but could sugars dissolve in the ether?? how do i identify if a flask needs washing or not if there are no black/brown particles in it???