After completing her Ph.D., Sherrill was promoted to associate professor of chemistry (1924) and then to full professor (1931).
She became department chair in 1946.
She and Emma Perry Carr became devoted friends, living, working, and traveling together.
Their colleague Lucy Weston Pickett was to recall: "She was very devoted to Miss Carr... and they worked very well together.
She was a good teacher and a good scientist in her own right, but somehow we thought of them together."

The chemistry department at Mount Holyoke was organized as a research group, in which faculty, master's students and undergraduates worked together.
Sherrill advocated the combination of teaching and active research investigation for its benefits to both teachers and students.
  The Mount Holyoke group investigated the ultraviolet spectroscopy of organic molecules.
Mary Sherrill's contribution to the group was the synthesis and purification of organic compounds, in preparation for spectroscopic examination.
This was essential work if the results of the analysis were to be meaningful.
 Sherrill worked initially with a Fery spectrograph, after 1926 with a Hilger quartz spectrograph, and after 1930 with a fluorite prism spectrograph.
Later the lab obtained two Beckman spectrophotometers.

In 1928-1929, Sherrill was awarded a fellowship to study new purification techniques being used overseas.
She visited Jacques Errera in Brussels and Johannes Diderik van der Waals in Amsterdam.
With Errera, she also studied the relationship between dipole moments and molecular structure.
 Mary Sherrill also visited in Europe in 1936, studying in Brussels, in Oxford, and at the University of Vienna.

During World War II, it became difficult to obtain quinine for the treatment of malaria.
Understanding the action of organic compounds and finding alternative treatments for malaria became an important area of work for the war effort.
  Sherrill and others including Emma Perry Carr, Mary Mercury Roth, Eleanor Anderson and Jean Crawford worked on the synthesis of antimalarial drugs for the wartime Office of Scientific Research and Development (OSRD).

Mary Sherrill published on a variety of topics including preparation and identification of chemical derivatives, isomerism, ring compounds, dipole moments and molecular constitution, pentenes, heptenes, methylbutene and quinazoline derivatives.
Her contributions were noted in the Annual Survey of American Chemistry (1930): "The preparation and purification of chlorides, bromides and iodides of normal heptane and the corresponding hydroxy-derivatives and the determinations of their dipole moments constitute valuable contributions".

The Vassar Chronicle (1948) reported "A constant and active researcher, Professor Sherrill has contributed to the knowledge of the relation between physical properties and molecular structure, and has developed the application of physical methods to the study of organic compounds."
After completing her Ph.D., Sherrill was promoted to associate professor of chemistry (1924) and then to full professor (1931). She became department chair in 1946. She and Emma Perry Carr became devoted friends, living, working, and traveling together. Their colleague Lucy Weston Pickett was to recall: "She was very devoted to Miss Carr... and they worked very well together. She was a good teacher and a good scientist in her own right, but somehow we thought of them together."
The chemistry department at Mount Holyoke was organized as a research group, in which faculty, master's students and undergraduates worked together. Sherrill advocated the combination of teaching and active research investigation for its benefits to both teachers and students.   The Mount Holyoke group investigated the ultraviolet spectroscopy of organic molecules. Mary Sherrill's contribution to the group was the synthesis and purification of organic compounds, in preparation for spectroscopic examination. This was essential work if the results of the analysis were to be meaningful.  Sherrill worked initially with a Fery spectrograph, after 1926 with a Hilger quartz spectrograph, and after 1930 with a fluorite prism spectrograph. Later the lab obtained two Beckman spectrophotometers.
In 1928-1929, Sherrill was awarded a fellowship to study new purification techniques being used overseas. She visited Jacques Errera in Brussels and Johannes Diderik van der Waals in Amsterdam. With Errera, she also studied the relationship between dipole moments and molecular structure.  Mary Sherrill also visited in Europe in 1936, studying in Brussels, in Oxford, and at the University of Vienna.
During World War II, it became difficult to obtain quinine for the treatment of malaria. Understanding the action of organic compounds and finding alternative treatments for malaria became an important area of work for the war effort.   Sherrill and others including Emma Perry Carr, Mary Mercury Roth, Eleanor Anderson and Jean Crawford worked on the synthesis of antimalarial drugs for the wartime Office of Scientific Research and Development (OSRD).
Mary Sherrill published on a variety of topics including preparation and identification of chemical derivatives, isomerism, ring compounds, dipole moments and molecular constitution, pentenes, heptenes, methylbutene and quinazoline derivatives. Her contributions were noted in the Annual Survey of American Chemistry (1930): "The preparation and purification of chlorides, bromides and iodides of normal heptane and the corresponding hydroxy-derivatives and the determinations of their dipole moments constitute valuable contributions".
The Vassar Chronicle (1948) reported "A constant and active researcher, Professor Sherrill has contributed to the knowledge of the relation between physical properties and molecular structure, and has developed the application of physical methods to the study of organic compounds."
Mary Lura Sherrill