Optimization of a class 100 clean room cabinet for electrothermal atomization AAS

A class 100 clean room laminar flow cabinet has been optimized with special emphasis to the particle emission characteristics of an electrothermal ato mizer for atomic absorption spectroscopy (ETA-AAS). A fume extraction devic e, operating in counterflow to the cleaned laminar flow, ensures that class 100 conditions in the vicinity of the autosampler are maintained even if h igh loads of matrix such as metal salts are released from the furnace durin g the pyrolysis or atomization steps. Under these conditions, the excellent detection limit performance of modern graphite furnace AAS can be obtained even for elements such as Ca, Fe or Zn, where fluctuation of the blank rat her than shot noise are usually limiting the detection power. When optimize d flow conditions are selected, the exhaust from the furnace is removed alm ost exclusively while only clean uncontaminated air is entering into the la boratory. This helps to protect the personnel and the laboratory environmen t from hazardous acidic fumes, solvents, and particulate metal salts.