preparation of stable hydrogen chloride standard gases...
TRANSCRIPT
TAKACHIHO TRADING CO., LTD.TAKACHIHO CHEMICAL INDUSTRIAL CO., LTD.
Kanako Nishi, Toshikatsu Hayase, Tsutomu Nakanoya
Jun Hashimoto, and Yusuke Yoshida
Preparation of Stable Hydrogen Chloride Standard Gases at Low Concentrations
8th APMP/TCQM Gas CRM Workshop
June 10th, 2010
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I. Background
II. Conditions to Make Low Concentration HCl Gas Standards
Ⅲ. Traceability
IV. Cylinder Treatment Methods
V. Stability Test
VI. Accuracy
VII. Conclusion
VIII.Current and Future Development Work
CONTENTS
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I. Background
Japan first passed legislation on HCl emissions in the 1960s
In 2006 Japanese Industrial Standard (JIS) revised the legislation to allow dry analytical method using gas standards
This led to:• Increased demand for HCl standard gas
• New requirements for low concentration HCl gas standards
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Ⅱ. Conditions to Make Low Concentration HCl Gas Standards
SI Traceability
Concentration Stability
(cylinder inner treatments are required)
Ⅲ. Traceabilty
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Gas Standard Preparation (SI Traceable)Preparation based on ISO-6142 (Gravimetric Method)
Analysis Method
Ion ChromatographyComparative analysis against Ion Chloride standard
solution per Japan Calibration Service System (JCSS)
III. Traceabilty (cont’d)A. Preparation of Gas Standard
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Use of high precision giant balance
Standard method based on SI Unit
Preparation of gas standard with small uncertainty and high accuracy
Model LK-100 LK-30
Maximum Capacity of Scale
100 kg 30 kg
Readability of Scale 1 mg 0.5 mg
III. Traceabilty (cont’d)B. Analysis Method
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1) Fill the glass vessel with the sample gas
2) Measure the pressure and temperature to calculate the moles (Gmol) of the sample gas
3) Add absorber liquid to the glass vessel
4) Agitate the glass vessel to absorb the HCl into absorber liquid
5) Analyze the concentration of the HCl in the absorber liquid by ion chromatography
B. Analysis Method (cont’d)
(Vol × Gatm) / (R × Gtemp ) = Gmol
(Gmol × HClc × Clg) / L = Ca
(Ca × L) / (Gmol × Clg) = HClc
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Gmol: Volume of extracted gas (mol)
Vol : Interior volume of sample cylinder (ℓ)
Gatm : Pressure of sample gas (atm)
Gtemp : Temperature of sample gas (K)
R: Gas constant (1 atm/mol K) 0.082057
HClc : Density of standard gas (mol/mol)
Clg : Molecular weight of Cl (g/mol) 35.453
L: Absorber Liquid volume (ℓ)Ca: Calculated volume of HCl in Absorbed Liquid (g/ ℓ)
Comparative analysis between standard solution and HCl 100 μmol/mol absorbed liquid
B. Analysis Method (cont’d)
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Reference Gas Concentration: 99.833 μmol/mol
Number of Samplings: 12 times
The HCl concentration in the gas standard is traceable and the analytical method is verified
Grav.Value(μmol/mol)
Analysis Value (Average)
(μmol/mol)
StandardDeviation
(μmol/mol)
99.833 98.889 1.457
T-Coat TM:Trademark of Takachiho’s unique and original cylinder inner treatment
IV. Cylinder Treatment Methods
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IV. Cylinder Treatment Methods (cont’d)Metal Coating (M.C.) and Cylinder Inner Treatments (C.I.T.)
1) M. C.
2) M. C. + Gas Aging (G.A.) (HCl)3) M. C. + T-Coat-I TM
4) M. C. + T-Coat-II TM
Concentration of HCl: HCl (90 μmol/mol) / N2
Measurement period: 180 Days
IV. Cylinder Treatment Methods (cont’d)
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Cylinder Treatment vs. Long-Term Stability
70
75
80
85
90
95
0 50 100 150 200
(days)
HC
l Con
c.
(μm
ol/m
ol)
1) M.C.
2) M.C.+G.A.
3) M.C.+ T-Coat-I
4) M.C.+ T-Coat-II
The HCl concentration in the (1) metal coating cylinder and (2) metal coating
plus gas aging cylinder declined about 10% after a few days
The HCl concentration of standard gas in the (3) metal coating plus T-Coat-I TM
cylinder declined 10% after 14 days
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The gas in the (4) metal coating plus T-Coat-II TM cylinder is very stable
T-Coat-II TM cylinder inner treatments was adopted and tested
IV. Cylinder Treatment Methods (cont’d)
70
75
80
85
90
95
0 50 100 150 200
(days)
HC
l Con
c.
(μm
ol/m
ol)
1) M.C.
2) M.C.+G.A.
3) M.C.+ T-Coat-I
4) M.C.+ T-Coat-II
V. Stability Test
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Gas: HCl/N2
Concentration: 75 μmol/mol
Number of sample cylinders: 5
Measurement period: 365 days
New gas standard:(prepared gravimetrically)
@ 3 months@ 6 months@ 12 months
V. Stability Test (cont’d)
40
50
60
70
80
90
100
0 100 200 300 400(days)
HC
l Con
c. (μ
mol
/mol
)
3
2
4
1
5
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Stable concentration for 12 months
Stability Test HCl/N2 (T-Coat-II TM)
6062646668707274767880
0246810Pressure (MPa)
HC
l Con
c. (μm
ol/m
ol)
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Pressure Dependence on HCl/N2 (T-Coat II TM)
Stable concentration between 1 MPa and 9 MPa
V. Stability Test (cont’d)
HCl / N2 T-Coat-II
HCl concentration of 100 μmol/mol was calculated using the equation below (uncertainty value of 95%)
U95 = √{(S)2 + (A)2} = 2.96 μmol/mol
A : Uncertainty of analysis ± 2.9μmol/mol(Standard deviation in 30 analyses)
VI. Accuracy
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U95 : Uncertainty value
S : Uncertainty of reference gas (gravimetrical method) ± 0.6μmol/mol
VII. Conclusion
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Metal Coating + T-Coat -II TM combinedperformed the best
The HCl concentration was stable for a minimum of 12 months
The concentration was stable at the minimum cylinder working pressure of 1 MPa
SI Traceable
VIII. Current and Future Development Work
To produce even lower concentration HCl gas standards(HCl 5μmol /mol N2 balance is in development)
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Stability of HCl 5μmol /mol N2 balance
3.03.54.04.55.05.56.0
0 100 200 300 400 500
(days)
HC
l Con
c.(μm
ol/m
ol)
VIII. Current and Future Development Work (cont’d)
To continue as pioneers by staying on the leading edge of
new environmental standards
To develop and test these standards as well as new
cylinder treatment processes for other reactive gas
standards
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Tel: +81-3-3444-0231Fax: +81-3-3444-0462E-mail:[email protected]://www.takachiho.biz
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Thank You For Your Attention!
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