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.