I am aware of the atmospheric composition and pressure. I am looking for research papers which state the mineral content of Martian soil.
According to NASA the answer is "Yes". Nitric oxide, which can be formed from pyrolysis of nitrates, evolved from heated samples of Martian soil.
Nitrates on Earth may be made by biological processes, but also by nonbioligical processes such as lightning. The NASA report gives no indication that the Martian nitrates are of biological origin.