How clean are NMR tubes out of the box?

A researcher recently wanted to know how clean NMR tubes were out of the box, and if there were organic contaminants on the glass. His question came from reading the below articles on NMR tube cleanliness that were posted on a manufacturer's website, and the AMMRL NMR discussion group. The concern is obvious, but the correct answer is different for each tube manufacturer.

“NMR tubes are not 'analytically clean' when delivered to you. So if your NMR samples require scrupulously clean glass, follow the procedures below for Difficult Cleaning Problems to assure your sample purity is never jeopardized. Since NMR tubes are formed over a metal mandrel and certain organic lubricants are used, these cleaning steps will assure that any trace organic or inorganic residues from these procedures is removed.”reference http://www.wilmad-labglass.com/services/NMR_010.jsp

I also found http://calmarc3.cchem.berkeley.edu/archives/ammrl/96/archive/0194.html where the marketing manager of the same company discusses out of the box NMR tube cleanliness.

Some other brands do not mention a specific manufacturing process, so pre-washing would seem logical based on reading the above.

It seems that some manufacturers use organic solvents routinely during the tube manufacturing process, and that contaminants are present in out of the box tubes.

Factually speaking, modern tube making processes have eliminated the use of petroleum oils and the like, strictly because of contaminant issues with customers. The mandrel process dates back to earlier times, when state-of-the-art tube making equipment was non-existent. As a matter of fact, Norell Brand NMR tubes are manufactured using a processes that uses no lubricants, organic solvents, or inorganic reagents.

It's hard to believe that for critical NMR applications, a manufacturer would employ antiquated use of petroleum oils in glass manufacturing, when better techniques are readily available.

So to answer the researcher's initial question, only Norell NMR tubes are completely free of metal and organic impurities, and that pre-washing Norell Brand NMR tubes is unnecessary.