Pauline Hald

Hald lived with her younger brother Walter for most of her life. She died in 1998, aged 94 years, in New Haven.

Hald worked as a biochemist based in New Haven. starting in the laboratory of John P. Peters at Yale School of Medicine. She was the first person to describe Peters' flame photometry technique for measuring sodium and potassium concentrations in blood samples. She was later director of the clinical chemistry laboratory at Grace-New Haven Hospital. In 1953 she addressed the Connecticut Society of Medical Technologists as a guest speaker. In 1957 she was one of the founding officers of the Connecticut section of the American Association for Clinical Chemistry.

From the 1930s to the 1960s, Hald's research was published in academic journals including Journal of Clinical Investigation, Journal of Biological Chemistry,American Journal of Physiology, and Methods in Medical Research. She also contributed to the textbook Standard Methods of Clinical Chemistry (1963).

Hald was born in New Haven, Connecticut, the daughter of Frank Xavier Hald and Josephine Merritt Hald. Her parents were immigrants; her father was born in Germany, and her mother was born in Nova Scotia. She graduated from Wellesley College in 1926.

Pauline Merritt Hald (February 2, 1904 – December 5, 1998) was an American clinical chemist and medical researcher, based in New Haven, Connecticut. She worked in the laboratory of chemist John P. Peters for many years, and published the first description of his flame photometry technique for measuring serum sodium and potassium levels.