自動化溫室效應氣體分析系統 之建立與應用 1 Speaker ： Ming-Xia Li Advisor ： Prof. Jia-Lin Wang Construction of an automated GC system for measuring atmospheric greenhouse gases

Introduction 2 GWP 100 ： ~ 408 ppm GWP 100 ： ~ 408 ppm GWP 100 ： ~ 326 ppb GWP 100 ： ~ 326 ppb GWP 100 ： ~ 2133 ppb GWP 100 ： ~ 2133 ppb

Analytical Techniques 3

4 Our analytical system Sampling system Sample automatically fills up to 700 torr Oven ： 70 ℃

5 Column Configuration CH 4 & CO 2 N2ON2O

Injection 6 Back-Flush 6 Actions O 2, N 2 O, other compounds other compounds O 2, N 2 O other compounds Sampling O 2, N 2 O N2ON2OO2O2

Channel switching 7 H2H2 Methanizer Composition ： 30 ~ 50% NiO (nickel(II) oxide) and 50 ~ 70% SiO 2 Function ： reduced CO 2 into CH 4 Temperature : 375°C CO 2 + 4H 2 → CH 4 + 2H 2 O CO 2 CH 4

Chromatograms 8 CO 2 FID ECD N2ON2O O2O2 CH 4

Experimental Carrier gases Oxygen cutting or not Parameter optimization 9

Different carrier gases – N 2 vs. CH 4 /Ar 10 N2N2 CH 4 /Ar When the carrier gas uses 5% CH 4 /Ar, the single of N 2 O will increase N2ON2O

Cutting oxygen or not 11 Not cut oxygen Cut oxygen When cut oxygen, the single of N 2 O just increase slightly, but the analyze time will increase N2ON2O O2O2

Optimize the parameters 12

Results and discussion Linearity Limit of Detection Reproducibility 13

Connecting with Vacuum System 14 vacuum system When system connects with vacuum system, makes sure samples are not be contaminated.

Quantitative – Working Standard 15 CO 2 CH 4 N2ON2O Standard Standard concentrations1788 ppb10 ppm Working standard signal Working standard concentrations ppm1873 ppb398 ppb Calibration curve - CO 2 Using NOAA standards to make calibration curves

Linearity 16 Pressure range ： 4 ~ 44 psi

Limits of Detection CO 2 CH 4 N2ON2O D.L. Concentration 3.42 ppm 364 ~ 408 ppm ppb 1758 ~ 2133 ppb 2.30 ppb 303 ~ 326 ppb Reproducibility CO 2 CH 4 N2ON2O RSD0.96%0.86%0.45% 17 Based on 3 times standard deviation N = 7 Pressure ： 4 psi Pressure ： 10 psi

18 Canister Analysis

Canister sampling in Taipei area in 2012 Sampling time ： 2012/02/14 05:00~06:00 am 18:00~19:00 pm 53 sampling sites Sampling time less than 1 min Monitoring compounds ： CFCs, CO 2, CH 4, N 2 O, NMHCs Look for emissions hot spots – sources of GHGs. 19 Ref. Chemosphere 1998, Vol.36, No. 10, Ref. Analytica Chimica Acta 2006, 576, 91-99

20 Evening (18:00 ~ 19:00) Morning (05:00 ~ 06:00) CO 2 Concentration range ： ~ ppmv

21 Evening (18:00 ~ 19:00) Morning (05:00 ~ 06:00) CH 4 Concentration range ： ~ ppbv

22 Evening (18:00 ~ 19:00) Morning (05:00 ~ 06:00) N2ON2O N2ON2O Concentration range ： ~ ppbv

Conclusions  The system measures CH 4 、 CO 2 、 N 2 O in 10 minutes for each sample.  It has very good reproducibility (RSD < 1%), and linearity (R 2 = ).  The limits of detection for CH 4 is ppb (vs. ~1.7 ppm), CO 2 is 3.42 ppm (vs. >360 ppm), and N 2 O is 2.3 ppb (vs. >300 ppb). 23

24 Thanks For Your Attention