Atomic absorption spectrophotometry has been critically evaluated as a method for the determination of traces of arsenic, lead, nickel, and zinc in copper. With careful matrix compensation, reliable (±5%–6%) results were obtained down to lower concentration limits of 0.025% for arsenic, 0.002% for lead, 0.003% for nickel, and 0.002% for zinc. Copper was found to interfere strongly with the determination of nickel in dilute nitric acid solutions. The use of the nitrous oxide–acetylene flame was found mandatory for the determination of arsenic. This work suggests at least limited applicability of atomic absorption to the problem of tracing the origin of ancient copper metal by impurity patterns.
Bruce Gandrud and John C. Marshall, "The Determination of Arsenic, Lead, Nickel, and Zinc in Copper by Atomic Absorption Spectrophotometry," Appl. Spectrosc. 24, 367-370 (1970)