👉 Bartlett's principle, also known as Bartlett's method or Bartlett's test, is a statistical method used in analytical chemistry and biochemistry for determining whether proteinaceous compounds are pure. It involves comparing the mass-to-charge (m/z) ratios of the two parent compounds to determine if they have identical molecular structures. The principle relies on the fact that the difference between the m/z values of two similar molecules is proportional to their ratio of charges, which can be calculated using a formula