Mini-volumes were used for collecting PM10 and
PM2.5 on 47 mm Whatman quartz microfiber filters in
the temples. The quartz filters were pre-heated at 900 °C
for 3 h to reduce the amount of organic vapors which
were absorbed on the filters. All filters were maintained
in a condition of 50% RH and 25 °C for over 48 h prior
to weighing on a microbalance with an accuracy of 1 μg
before sampling. The exposed filters were unloaded
from filter holders immediately after sampling and
stored in a refrigerator at about 4 °C until conducting
chemical analysis to prevent the evaporation of volatile
compounds. Operation blank samples which were processed
simultaneously with field samples were collected
to access the adsorption of organic components onto the
filter during sampling. The blank filters were deducted
from the field sample results to reduce the error due to
gas adsorption artifact.