The observation of unusually large blank values in the cold-vapor atomic absorption analysis for total mercury

Anomalously high blank values (1000 X normal) have been observed when cold-vapor atomic absorption analysis for total mercury follows analysis for inorganic mercury. The origin of this unexpected phenomenon is considered to be accumulated chemisorption and possible deep embedment of mercury from previous samples within the reaction vessel. Detection of this mercury follows CdCl2-induced desorption. Precautionary measures are suggested.