The New York Times article NASA Rover on Mars Detects Puff of Gas That Hints at Possibility of Life describes the newest detection of a "whiff" of methane on Mars.
The article states that the level was 21 ppb, the largest concentration ever reported:
When Curiosity arrived on Mars in 2012, it looked for methane and found nothing, or at least less than 1 part per billion in the atmosphere. Then, in 2013 it detected a sudden spike, up to 7 parts per billion that lasted at least a couple of months.
The methane ebbed away.
The measurement this week found 21 parts per billion of methane, or three times the 2013 spike.
Even before this week’s discovery, the mystery of methane has been deepening.
Curiosity scientists developed a technique that enabled the rover to detect even tinier amounts of methane with its existing tools. The gas seems to rise and fall with the red planet’s seasons. A new analysis of old Mars Express readings confirmed Curiosity’s 2013 findings. One day after Curiosity reported a spike of methane, the orbiter, passing over Curiosity’s location, also measured a spike. (emphasis added)
I am wondering if the Mars 2020 rover will have a trace gas detection capability the same as Curiosity's, or if it is improved in any way, building on experience gained from analysis using what the developed "...technique that enabled the rover to detect even tinier amounts of methane with its existing tools."