Argon Gas Humidifier 7800 ICP-MS

Question

Hi everyone, 
 I&rsquo;m working with an ICP-MS 7800, and we recently installed an argon gas humidifier to improve our analysis of samples with high sodium content. The goal was to enhance our percent recoveries. Can anyone share insights on whether the humidifier is more effective in General Purpose mode or HMi mode? Your advice would be greatly appreciated. 
 Thank you!

Efstathios.Sianos · Answer

Hi Villy, the function of argon gas humidifier is to help the user avoid blockage of the nebulizer due to high salt content is his sample, like you high sodium content application. So, if you were seeing previously increase on your nebulizer back pressure, when running samples this means some salt is condensing on the tip of the nebulizer and blocking the accessory. With the Ar gas humidifier, the neb. gas is coming humid and then dissolving these blockages and I am expecting a better nebulizer stability and of course better measurement stability. The Agilent Ar humidifier 2nd channel is also keeping humid the dilution gas, when you are running HMI mode. Theoretically the Ar humidifier should not affect your counts, your signal stability and should produce the same results even if you are using general purpose or HMI, so personally I do not see a connection there. Also when the sodium content is really high (total dissolved solids going over 0.2 - 0.3%) we always suggest running your samples on HMI mode. Please observe you long time stability and if you see a big ISTD downwards drift, maybe you have to increase the HMI from 4 to 8 or even 25.