Stability Assessment of Gas Mixtures Containing Monoterpenes in Varying Cylinder Materials and Treatments

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1 Stability Assessment of Gas Mixtures Containing Monoterpenes in Varying Cylinder Materials and Treatments Jerry Rhoderick and Janice Lin Analytical Chemistry Division National Institute of Standards and Technology 100 Bureau Drive, MS-8393 Gaithersburg, Maryland USA 4th WMO-VOC meeting on Global Observations of VOCs September 12, 2012 York, United Kingdom

2 Ratios of terpenes to benzene with time in mixture ND02744 Aluminum Aculife Cylinder

3 Tracking the growth/degradation rates for ß-pinene, α-pinene, R-limonene, p-cymene and camphene in mixture ND02744

4 Publications on ß-Pinene and α-pinene Isomerization Foletto E, Valentini A, Probst L, Porto L., Gas-phase ß-pinene isomerization over acid-activated bentonite. Latin American Applied Research 32(2). Allahverdiev A, Gündüz G, Murzin D., Kinetics of α-pinene isomerization. Industrial Engenering and Chemical Research 37, Findik S, Gündüz G., Isomerization of α-pinene to camphene. JAOCS 74(9),

5 Concentration of Standards Prepared Experis Treated Aluminum Nickel-Plated Carbon Steel D D Y Y Y Analyte x a u(x) b x a u(x) b x a u(x) b x a u(x) b x a u(x) b α-pinene ß-Pinene Carene ,8-Cineole Myrcene R-Limonene p-cymene Camphene n-hexane Benzene

6 RATIO Data and Statistics for Ni plated steel Y 3-Carene 1,8-Cineole β-pinene α-pinene p-cymene Camphene R- Limonene Days DateTime Ratio U(Rat) Ratio U(Rat) Ratio U(Rat) Ratio U(Rat) Ratio U(Rat) Ratio U(Rat) Ratio U(Rat) 1 23-Mar Mar Mar Apr Apr Apr Apr Apr Apr Apr Apr May May May May Jun n Average Stdev %RSD 1.77% 1.12% 1.69% 3.44% 4.27% 12.24% 4.68% Slp; Intr u(slp); u(intr) R 2 ; RMSE slp /u(slp) p

7 Minor Component Peak Area Ratios Major Component Peak Area Ratios Major Monoterpene and Minor (Impurity) Analyte Ratios in CSNi-92Y Carene 1,8-Cineole ß-Pinene α-pinene p-cymene Camphene R-Limonene Initial Linear Trend Time, Days from Preparation

8 Minor Component Peak Area Ratios Major Component Peak Area Ratios Major Monoterpene and Minor (Impurity) Analyte Ratios in CSNi-87Y ß-Pinene 1,8-Cineole 3-Carene α-pinene Camphene p-cymene R-Limonene Initial Linear Trend Time, Days from Preparation

9 Minor Component Peak Area Ratios Major Component Peak Area Ratios Major Monoterpene and Minor (Impurity) Analyte Ratios in CSNi-93Y ß-Pinene 3-Carene 1,8-Cineole α-pinene Camphene p-cymene R-Limonene Initial Linear Trend Time, Days from Preparation

10 Major Monoterpene and Minor (Impurity) Analyte Ratios in Al-Experis D646508

11 Ratios Ratios Major Monoterpene and Minor (Impurity) Analyte Ratios in Al-Experis Camphene β-pinene D p-cymene R-Limonene 3-Carene 1.6 Initial Linear Trend Myrcene α-pinene n Average Stdev %RSD 0.65% 0.20% 0.31% 0.36% 0.41% 2.02% 15.96% Camphene ß-Pinene p-cymene R-Limonene 3-Carene Myrcene α-pinene Slp Intr u(slp) u(intr) R RMSE slp /u(slp) Prob Days

12 Ratios for ß-pinene in CSNi-92Y, CSNi-87Y, CSNi-93Y, Al-Experis-07, and Al-Aculife Cylinders.

13 Gravimetric Concentration of Additional Standards Prepared Aluminum Experis Treated Experis Treated Aluminum D (20L) D (10L) Analyte x a u(x) b x a u(x) b α-pinene ß-Pinene Carene ,8-Cineole R-Limonene p-cymene Camphene n-hexane

14 Major Monoterpene Analyte Ratios in Remake Al-Experis D n Average Stdev %RSD 0.35% 0.38% 0.39% 0.35% α-pinene ß-Pinene 1,8-Cineole 3-Carene Slp Intr u(slp) u(intr) R RMSE slp /u(slp) Prob

15 Bi-lateral comparison with NIST

16 Values of NPL Standard vs NIST Standards

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18 Results from Round Robin of ppt Hydrocarbon Mixture

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20 Where do we go from here? develop several standards at higher concentration nmol/mol - verify concentrations prepare several 2-5 nmol/mol standards by dilution from higher concentration - verify gravimetric concentrations - compare to older 1-step standards - this procedure will lower the uncertainties substantially

21 Conclusions Air Products aluminum w/experis treatment very promising - nickel plate steel cylinders show degradation but a much slower rate than Aculifed aluminum results indicate stable (365+ days) mixtures of α-pinene, ß-pinene, 3-carene, p-cymene, R-limonene, camphene -1,8-cineole at 70+ days