Isotopic Water Liquid Analyzer, L1102-i10-6-08

2

Introduction

• High precision analyzer for isotopic ratio measurements from water samples

• Significantly lower cost of ownership than competing technologies– Negligible maintenance costs

• Picarro WS-CRDS analyzer– Same for vapor & liquid applications

• Temperature regulated vaporizer system– Designed for minimal memory effects

• High precision autosampler– accurate and reproducible small

volume injections

3

Large Permil Range, No Calibration

• 4 separate groundwater samples, first injection discarded– 300 permil range δD– 50 permil range δ18O

– Run without calibration– Minimal memory effects

-40 -30 -20 -10 0 10-350

-300

-250

-200

-150

-100

-50

0

4

Maintained Precision

• Single sample expanded– Excellent precision

maintained for multiple injections

-40 -30 -20 -10 0 10-350

-300

-250

-200

-150

-100

-50

0

-15.0 -14.8 -14.6 -14.4 -14.2

-126.5

-126.0

-125.5

-125.0

-124.5

-124.0

δD std. dev. = 0.29

δ18O std. dev. = 0.08

5

Analyzer Main Window

Software window that displays and controls the general functionality of the analyzer. Also used when analyzer is configured for vapor-only operation.

•H2O concentration serves as a measure of injection consistency

•Choose measurement for graph window and precision

•Analyzer status

6

Pulse Analyzer

Software window that allows real-time visualization and analysis of individual sample injections when the analyzer is measuring liquid samples. Allows inspection of water concentration and isotopic content for each injection.

•Data quality visualization and monitoring in real time•Real-time calculation of measurement statistics

7

Coordinator Window

Software window that displays and saves summarized results of analysis for each liquid injection. Data including date/time, injection method and quality, isotopic content and statistics are recorded and displayed

for each injection. Allows user to load a file containing sample descriptions. Saves data to a text file.

8

Picarro L1102-i, Guaranteed Specifications

9

Picarro L1102-i, General Characteristics

• Simultaneous measurement of δ18O and δD• High precision (typically δ18O < 0.1‰, δD <0.5‰)

• Minimal memory and drift

• Rugged and insensitive to changes in ambient temperature

• Large dynamic range with high linearity

• Installed and operational in minutes

10

Excellent Accuracy and Precision

• Repeated measurements of same groundwater sample measured on IRMS and Picarro analyzer: water sample #1

Picarro Analyzer Precision and Intercomparison with IRMS

-78

-77.8

-77.6

-77.4

-77.2

-77

-76.8

-76.6

-11.45 -11.4 -11.35 -11.3 -11.25 -11.2 -11.15 -11.1

δδδδ18O (‰ vs. V-SMOW)

δδ δδD (

‰ v

s. V

-SM

OW

)

Picarro meanIRMSPicarro

Specificaion limits shown: δ18O: ±0.1‰, δD: ±0.3‰

11

Picarro vs. IRMS

• Repeated measurements of same groundwater sample measured on IRMS and Picarro analyzer: water sample #2

Picarro Analyzer Precision and Intercomparison with IRMS

-114.2

-114

-113.8

-113.6

-113.4

-113.2

-113

-112.8

-16 -15.95 -15.9 -15.85 -15.8 -15.75 -15.7 -15.65 -15.6

δδδδ18O (‰ vs. V-SMOW)

δδ δδD (

‰ v

s. V

-SM

OW

)

Picarro meanIRMSPicarro

Specificaion limits shown: δ18O: ±0.1‰, δD: ±0.3‰

12

Picarro vs. IRMS

• Repeated measurements of same groundwater sample measured on IRMS and Picarro analyzer: water sample #3

Picarro Analyzer Precision and Intercomparison with IRMS

-95.6

-95.4

-95.2

-95

-94.8

-94.6

-94.4

-13.7 -13.65 -13.6 -13.55 -13.5 -13.45 -13.4

δδδδ18O (‰ vs. V-SMOW)

δδ δδD (

‰ v

s. V

-SM

OW

)

Picarro meanIRMSPicarro

Specificaion limits shown: δ18O: ±0.1‰, δD: ±0.3‰

13

Precision and Stability Data

• Data recorded continuously for ~3 days – without calibration• Continuous injections of the same sample• 10-minute injection to injection time

Long-Term Analyzer Drift PerformanceWithout Calibration

-70

-69

-68

-67

-66

-65

-64

-63

-62

-61

-60

234.5 235 235.5 236 236.5 237 237.5

Time (days)

δδ δδD (‰

)

-8

-7.8

-7.6

-7.4

-7.2

-7

-6.8

-6.6

-6.4

-6.2

-6

δδ δδ18O

(‰)

Standard deviation over 3 days:

δ18O: 0.074 ‰ δD: 0.26 ‰

Run under normal laboratory ambient temperature conditions

14

Temperature Stability Data:

Data showing the analyzer’s extremely high stability even in conditions of varying ambient temperature. Analyzer was run in a temperature-controlled chamber – samples were analyzed continuously as the

temperature was changed.

Temperature Sensitivity

Trendline: 0.083‰ / ºC

-10

-9.5

-9

-8.5

-8

-7.5

-7

-6.5

-6

32 33 34 35 36 37 38 39 40 41 42

Ambient Temperature (ºC)

δδ δδD ‰

-70

-68

-66

-64

-62

-60

-58

-56

-54

δδ δδ18O

‰

Trendline: 0.012‰ / ºC

15

Memory Coefficients (δ18O)

Memory Coefficients: δδδδ18O

0.97

0.975

0.98

0.985

0.99

0.995

1

1.005

1.01

0 1 2 3 4 5 6 7 8 9 10

Injection Number

Mem

ory

Coe

ffici

ent

-36 to -7 permil

-7 to 86 permil

86 to -6 permil

Data showing the analyzer’s extremely low memory even when adjacent samples vary significantly in isotopic content

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Memory Coefficients (δD)

Memory Coefficients: δδδδD

0.93

0.94

0.95

0.96

0.97

0.98

0.99

1

1.01

0 1 2 3 4 5 6 7 8 9 10

Injection Number

Mem

ory

Coe

ffici

ent

-300 to -65 permil

51 to 913 permil

913 to -60 permil

Data showing the analyzer’s extremely low memory even when adjacent samples vary significantly in isotopic content

17

Picarro vs. IRMS – typical data

18

Brine Experiment

• Total 841 injections of 4% briny water• 6 days of non-stop data acquisition• ~ 65 mg salt, 1618.4 µL water

• Previous experiments indicate ~ 150 mg of salt before inconsistent water concentration as reported by the instrument

19

Memory Coefficients for δ18O, briny water

0.97

0.975

0.98

0.985

0.99

0.995

1

1.005

0 1 2 3 4 5 6 7 8 9 10

Injection Number

Mem

ory

Coe

ffici

ents

First series of injections, 1st vial~ 600 injections later.first 9 injections, last vial

• Memory is exceptionally low– 97 - 98% of delta for injection 1– ~ 99.5% at injection 3

• Remarkably stable with high salt loading

20

Memory Coefficients for δD, briny water

0.94

0.95

0.96

0.97

0.98

0.99

1

1.01

0 1 2 3 4 5 6 7 8 9 10

Injection Number

Mem

ory

Coe

ffici

ents

• Memory is exceptionally low– 95 - 96% of delta for injection 1– ~ 99.0% at injection 3

• Remarkably stable with high salt loading

First series of injections, 1st vial~ 600 injections later.first 9 injections, last vial

21

Consistent H2O Concentration

0

5000

10000

15000

20000

25000

0 1 2 3 4 5 6 7 8 9 100

5000

10000

15000

20000

25000

0 1 2 3 4 5 6 7 8 9 10

• Measurement of H2O concentration from sequential early injections– H2O concentration used as a

measure of injection quality

• Measurement of H2O concentration from sequential injections in the last series, about 800 injections later

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Briny Samples Conclusion

• Precision generally remains within the specifications of the instrument for both isotopes

• The memory coefficients for δ18O and δD are exactly the same as they are for clear water

• The drift data (same sample was measured multiple times every 24 - 40 hrs) shows no pattern indicating deterioration of instrument performance

• No difference in any aspect of performance even after injecting 65 mg of salt

• The evaporator cleaning process takes about a total of 1 hr including taking the evaporator apart (20 mins), cleaning process (20 mins) and putting it back together (20 mins).

23

Picarro – Optimized Vaporizer Design

• Vaporizer and tubing thermally enclosed

• Tubing lengths minimized for minimal memory

• Separate vaporizer vacuum pump for efficient operation

• LED readouts for vaporizer temperature set and actual