You didn't specify the country for this application, the industry, or the classification, so it's difficult to answer very directly. You might contact one of the analyzer companies such as Ametek, Siemens, or Yokogawa and ask them to supply analyzers to your client. They have been doing this for a long time and understand the instruments.
"Well, I've wrestled with reality for 35 years, Doctor, and I'm happy to state I finally won out over it." Elwood P. Dowd
It sounds as though you have your work cut out for you. If you can remember only one thing, let it be that 1% = 10,000 ppm. So, 10% would be 100,000 ppm, etc. You will need to determine whether the concentration is by weight or volume. Talk with the instrument manufacturers to fill in the blanks.