TITLE
Laboratory Evaluation of Method 0050 for Hydrogen Chloride

AUTHOR(S)
Joette Steger, Denny Wagoner, Joan Bursey, and Raymond Merrill,
Radian; Robert Fuerst and Larry Johnson, EPA

PERFORMING ORGANIZATION NAME AND ADDRESS
Radian Corporation
Box 13000
Research Triangle Park, NC  27709


SPONSORING AGENCY NAME AND ADDRESS
Atmospheric Research and Exposure Assessment Laboratory, U. S.
Environmental Protection Agency
Research Triangle Park, NC  27711

ABSTRACT
     The EPA reference method used for collecting hydrogen chloride
and chlorine in stack gas emissions is SW-846 Method 0050.  In
Method 0050 gaseous and particulate pollutants are withdrawn from
the stack at a rate proportional to the flow rate of the gas
emissions through the stack and are collected in a cyclone, on a
filter, and in absorbing solutions.
     Laboratory experiments were conducted to examine three issues
concerning Method 0050; how do you handle the wet hydrogen chloride
collected in the cyclone?; can this method be used to collect very
low concentrations of hydrogen chloride?; can the presence of
ammonium chloride in the stack emissions cause the method to have
a positive or negative error?
     As the method requires, the cyclone is purged at the end of
sampling with clean ambient air.  These studies showed that this
was an effective way to transfer the residual hydrogen chloride
from the cyclone to the impingers as long as no more than 25 ml of
liquid was collected in the cyclone.  Otherwise, the cyclone
solution must be returned to the laboratory where further
procedures must be used,.
     At very low concentrations hydrogen chloride appears to be
lost in the sampling equipment before being collected in the
absorbing solutions and the loss appears to increase as the
moisture content of the stack emissions increase.
     The presence of ammonium chloride introduces a positive error
under all condtions tested.