I'm just a noob but I can pass on this link/ study that measured the amount of nicotine in tobacco Chews.
Determination of Nicotine, pH, and Moisture Content of Six U.S. Commercial Moist Snuff Products -- Florida, January-February 1999
Good luck to you and your Mom and yes, it is a wonderful thing you're doing.
Determination of Nicotine, pH, and Moisture Content of Six U.S. Commercial Moist Snuff Products -- Florida, January-February 1999
Good luck to you and your Mom and yes, it is a wonderful thing you're doing.