Implementation Manual
for the 11 Inter-laboratory Comparison Project on Dry Deposition
2015
th
1. Purpose
This Inter-laboratory Comparison Project is conducted to improve the accuracy of dry
deposition monitoring among the laboratories in EANET countries. The purposes of this
project are:

To recognize the precision of analytical equipment and the performance of its
operator by obtaining information on the accuracy of measurements in each
participating laboratory, and consequently take this opportunity to improve the
quality of the analysis on acid deposition monitoring, and
 To find advantages and disadvantages of the analytical methods and improve
reliability of analytical data through the assessment of analytical procedures.
2. Method
(1) Participating laboratories
Laboratories in charge of chemical analysis for the filter pack method of dry deposition
monitoring in EANET shall participate in this survey.
(2) Activities
Six kinds of filter samples placed in centrifuge tubes (hereafter referred to as
“samples”) are distributed to the participating laboratories. Known amounts of anion were
added to 2 samples, and known amounts of cation were added to the other 2 samples.
Blank samples are prepared for alkali and acid impregnated filters. The list of the filter
samples are shown in Table 1. The laboratories are required to analyze 3 samples of each,
and submit their results to the Network Center (hereafter referred to as “NC”). The
analytical precision and accuracy of the submitted data from each participating laboratory
are evaluated with statistical analyses.
(3) Analytes
All participating laboratories are required to analyze the following analytes: chloride
ion (Cl-), sulfate ion (SO42-) (from the filter samples impregnated with K2CO3), and
ammonium ion (NH4+) (from the filter samples impregnated with H3PO4) on the filters.
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3. Outline of filter samples
Table 1
Name
Details
List of filter samples
Container
Number of
samples
Note
No.151d-1
Alkali (K2CO3)impregnated filter
Polyethylene
centrifuge tube
3
Two kinds of the standard solutions
which contained known quantity of
sulfate or chloride ion were added.
No.151d-2
Acid (H3PO4)impregnated filter
Polyethylene
centrifuge tube
3
One kind of the standard solution
which contained known quantity
of ammonium ion was added.
No.152d-1
Alkali (K2CO3)impregnated filter
Polyethylene
centrifuge tube
3
Two kinds of the standard solutions
which contained known quantity of
sulfate or chloride ion were added.
No.152d-2
Acid (H3PO4)impregnated filter
Polyethylene
centrifuge tube
3
One kind of the standard solution
which contained known quantity
of ammonium ion was added.
No.153d-1
Alkali (K2CO3)impregnated filter
Polyethylene
centrifuge tube
3
Blank
No.153d-2
Acid (H3PO4)impregnated filter
Polyethylene
centrifuge tube
3
Blank
4. Analysis
(1) Outline of extraction and filtration procedure
Filter samples are put in centrifuge tubes, and then the extracting solvents are directly
added into the tubes. The extraction and filtration procedures are specified in the
“Technical Manual for Air Concentration Monitoring in East Asia, December 2013”
(hereafter the “Air Concentration Manual”). The detailed procedure is as follows;
=Extraction=
a) Sample No.151d-1, No.152d-1, No.153d-1
Add 20 mL of H2O2 solution (0.05 %-v/v) as an extracting solvent into each centrifuge
tube.
b) Sample No.151d-2, No.152d-2, No.153d-2
Add 20 mL of pure water (EC<0.15 mS/m) as an extracting solvent into each centrifuge
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tube.
c) Shake for at least 1 minute to ensure sample contact with all inside surfaces.
d) Rotate/swirl the centrifuge tube thoroughly to contact all inside surfaces.
e) Set shakers and start shaking for 20 min, or shake each tube by hand sufficiently.
=Filtration=
Remove insoluble matter from the solution using a membrane filter (pore size: 0.45μm).
The membrane filter must be prewashed with pure water (more than 100 mL) before
filtration. After filtration, those filtrates are assigned identification numbers and sealed
tightly.
Note 1) Carry out the analysis immediately after extraction.
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Note 2) It is strongly recommended that the filtrates should be analyzed immediately
after extraction, however, in case that they need to be kept for any reasons,
store them in a refrigerator at 4 ºC.
Note 3) The expiration date for the samples is December 31, 2015, therefore, analysis
must be completed by that date.
(2) Analytical method
The participating laboratories are expected to use the analytical method specified in the
“Technical Manual for Wet Deposition Monitoring in East Asia- 2010, November 2010”
(hereafter the “Wet Manual”). Analytical methods specified in the Wet Manual are shown
in Table 2.
Table 2
Analytical methods specified by the Technical Manual
Parameter
-
Cl ,
SO42-
NH4+
Analytical method
Ion Chromatography (preferably with suppressor) or Spectrophotometry
Ion Chromatography or Spectrophotometry (using indophenol blue)
(3) Submission of the results
All participating laboratories are requested to report as the net quantity of each ion
(SO42-, Cl-, and NH4+) in samples.
Each quantity (Msol) is calculated as follows:
Msol = Csol x Vsol
(1)
where
Msol : quantity of each component in the filtrate (μg);
Csol : concentration of each component in the filtrate (mg L-1);
Vsol : volume of the solvent (20 mL);
The net quantity of each ion (net Msol) is calculated as follows:
net Msol
,where
= Msol, Sample
−
Msol, Blank
(2)
net Msol: net quantity (μg) of each ion on the filter.
Msol, Sample: quantity (μg) of each component in the filtrate (No.151d-1,
No.151d-2, No.152d-1 or No.152d-2);
Msol, Blank: the median value (μg) of the 3 blank filtrates (No.153d-1 or
No.153d-2).
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Note 4) net Msol is automatically calculated by entering their values of Msol, Sample and
Msol, Blank on the Excel file.
Note 5) The median value of 3 blank samples was adopted according to the Air
Concentration Manual.
5. Calibration
At least 5 calibration solutions, including the solution in which the concentration of
each ion is “0 μmol L-1” (Std0), are required to generate a suitable calibration curve. Each
concentration value is rounded to 2 decimal places.
6. Detection Limit and Determination Limit
In the process of determining the detection limit and the determination limit, each
concentration of the lowest standard solution (Std1) should be measured 5 times. The
detection limit and the determination limit are calculated from the standard deviation(σ)
of 5 measurements as follows:
Detection limit = 3σ (μmol L-1)
Determination limit = 10σ (μmol L-1)
Note 6) Once the analysis results are entered on Report [2], 3σ and 10σ are
automatically calculated.
7. Other Notes
1) Extraction, filtration, and analysis should be done on the same day once you open
the bag (or taking off a lid of a centrifuge tube). In particular, special care for 151d-2,
152d-2, and 153d-2 to determine the quantity of NH4+ will be needed. (Be aware that
sample solutions may be contaminated by ammonia in a laboratory. Even samples set in
an autosampler may be possibly contaminated by ammonia during longer analysis time.)
2) It is strongly recommended that only analysis of the interlaboratory samples should
be conducted in one sequence in order to minimize contamination during analysis.
Regular samples should not be analyzed simultaneously with the interlaboratory samples.
8. Preparation of the report
Complete the attached report format [1] to [6] in accordance with the following points.
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Report format [1]
Enter the names of your country, the organization, the analyst(s) who determined the
samples, and enter the numbers of Tel and Fax in the cells. Enter the determined values
in Table 1 and the blank values in Table 2. Enter the values only in yellow highlighted
cells. All values are rounded to 3 significant digits. The values in Table 3 are
automatically calculated and appeared by filling Table 1 and Table 2.
Report format [2]
Enter 5 analysis values of each lowest standard solution (Std1) only in light blue
highlighted cells. Averages, standard deviations, detection limits, and determination
limits are automatically calculated.
Report format [3]
Enter the concentration values of the standard solutions used for calibration. Each
concentration value is rounded to 2 decimal places. The names of your country, the
organization, the analyst(s) who determined the samples, Tel and Fax are automatically
appeared by filling Report format [1].
Report format [4]-[6]
Enter all items or check from some choices, and then complete the format [4] to [6].
If you have any questions about the report formats, send e-mail to datasubmit@acap.asia.
9. Submission of all documents
Submission documents are summarized as follows. All documents should be submitted
via e-mail.
(i) File : 2015Dry_Report1-6_format.xlsx (Report [1] to [6])
Fill the necessary data and items on each sheet.
(ii) Copies of each calibration curve (SO42-, Cl- , NH4+)
Append copies of each calibration curve on the “calibration curve” sheet of
2015Dry_report1-6_format.xlsx. Or send as the separated files.
(iii) Copies of the analysis chart for Std1 (SO42-, Cl- , NH4+)
Append copies of the analysis chart for Std1 on the “Std1” sheet. Or send as the
separated files.
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(iv) Each copy of the analysis charts of the Sample No.151d-1, No.151d-2, No.152d1, No.152d-2, No.153d-1, and No. 153d-2 (SO42-, Cl- , NH4+)
Append copies of the analysis charts on the “Analysis Chart” sheet. Or send as the
separated files.
10. Deadline of the reporting document submission
February 29, 2016.
All samples must be analyzed by December 31, 2015.
11. Address
Submit all documents to the NC through the National QA/QC managers of each
participating country. The contact address of the NC is as follows. Please be aware that
e-mail address was changed.
Kumiko NAKAMURA, Ms.
Ken YAMASHITA, Dr.
Data Management Department
Asia Center for Air Pollution Research
1182 Sowa, Nishi-ku, Niigata-city, Niigata 950-2144 Japan
Tel: +81-25-263-0562
Fax: +81-25-263-0567
E-mail: datasubmit@acap.asia
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