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c) Wash the
hands thoroughly with soap and water before operation. Avoid
touching objects other than the analytical tools or instruments.
In particular, be sure to wash the hands every time touching the
door knob.
d) Cover the bench with aluminum foil, which must be replaced
everyday.
e) Clean the evaporator by distilling acetone of the PAE
analysis grade to dryness immediately before use.
f) Handle the standard chemicals on a bench other than that for
analysis.
g) Never let the pipette tips touch other tools, instruments,
etc.
h) Handle the one-mark pipettes in the standard way; never use
the mouth to drive the liquid off.
i) Take the watch off before operation.
j) Keep the hair tidy.
k) Keep the nails short. 2 This method uses surrogates as the internal standards for
collection of the recovery ratio. The average recovery ratio is
98.8-148% and relative standard deviation is 0.4-7.8% when the
surrogates are added to feeds so that the concentration of DBP,
BBP and DEHP is 100 ng/g each and that of DiOP and DiNP 500 ng/g
each.
3 This procedure is applicable to analysis of litter. Use
acetone for extraction, remove the acetone by distillation under
reduced pressure, extract PAEs from the residue by n-hexane, and
purify the extract by the Florisil-PSA column
4 Do not use long after the first opening of the package because
of possible contamination by PAEs from the environment.
5 If the water used gives interfering peaks, repeat washing with
n-hexane.
6 Always perform blank test to determine the quantity of PAE
that enters the analytical system during the session, because
contamination from the environment can be problematic in PAE
analysis.
7 It is recommended to check the performance of the GC/MS by
injecting only n-hexane a few times before measurements of
standards and samples.
8 E.g. Agilent technologies' HP-5MS and HP-5MS SV, or J&W
Scientific's DB-5MS.
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