Meeting the Requirements of ASTM D 6591-06 ( … · Meeting the Requirements of ASTM D 6591-06 ( IP548/06 ) with Agilent 1200 LC Systems ... ASTM D 6591-06 Calibration Standard A

Meeting the Requirements of ASTM D 6591-06 ( IP548/06 ) with Agilent 1200 LC Systems

M.Woodman, Chemical Analysis Solutions Unit, Wilmington, Delaware, USA

M.Sierocinska, European Field Support Centre, Waldbronn, Germany

EN12916/IP391 Update

September, 2009

Agenda

• What is the source and application for ASTM D 6591-06 (and IP548/06)?

• Description of Recent ASTM D 6591-06 Method Updates • New D 6591-06 / IP548/06 Method Requirements • Alternate methods for biodiesel blends • Recommendations for the best configuration • Results from locally collected diesel samples • Summary

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September, 2009

Usage and Source of ASTM/IP/EN methods used

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September, 2009

ASTM D 6591-06 and IP548/06 measure aromatic hydrocarbon groups in petroleum distillates having specified boiling point ranges of 150-400oC. These methods are mainly applied to fuel analysis, particularly diesel motor fuel. Kerosene based fuels for aviation are covered by another related method

ASTM (www.astm.org) is the source of ASTM methods. The Energy Institute (www.energyinst.org.uk) is the source of the IP (sometimes referenced as EI) methods

IP (or EI) and EN methods (European Committee for Standardization http://www.cen.eu/cen/pages/default.aspx ) often have parallel ASTM methods

The method revision designation is very important

http://www.astm.org/�

http://www.energyinst.org.uk/�

http://www.cen.eu/cen/pages/default.aspx�

Related IP, EN and ASTM Methods

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September, 2009

IP Method and Revision

Method Overview

Special Parameters

ASTM Method?

Comments

IP391/07 150-400oC diesel fuel petro/bio blends up to B-5

no backflush

amino and/or cyano column

no equivalent available at this time

same as method EN12916:2006

MAH, DAH, Tri+AH reported

IP548/06 150-400oC diesel fuel

backflush required


D-6591-06 MAH, DAH, Tri+AH reported

FAME interferes with result

IP436/01 50-300oC

aviation fuel, kerosene

no backflush


D-6379-04 MAH and DAH reported

not for samples with Tri+AH

General Conditions and Schematic of ASTM D 6591

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September, 2009

Mobile phase: n-heptane at 1ml/min flow rate

Column: Amino-propyl and/or Amino-Cyano-propyl bonded phases. Amino-propyl 4.6x250mm 5um is commonly used

Column Temperature: approx. 20-25oC

Detection: Refractive Index

Special Feature: 6 port valve for backflushing the column to elute tri+ aromatics as a single peak

General Schematic of ASTM D 6591-06

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September, 2009

Figure 1, Agilent publication 5965-9044E

Recent HGA Method Updates: ASTM D6591-06

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September, 2009

• Terms redefined • more specific description of polyaromatics adopted

• Designate a new IP method correlation • IP391-95 (used with ASTM D 6591-00) replaced by IP548/06

• Exclusion or warning regarding Bio/Petrodiesel Blends • the method recognizes difficulties with biodiesel fuel blends and

refers the analyst to IP391/07 (EN12916:2006) for samples containing biodiesel (FAME) components

• due to inclusion of FAME components in the tri+AH backflush peak, erroneously high tri+ aromatic results are reported if D6591-06 is used with biodiesel blends

• unusually high tri+AH results with this method should be investigated to determine if unsuspected FAME is present due to fuel contamination or mislabeling

General Conditions and Schematic of D 6591-06

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September, 2009

ASTM D 6591-06 System Performance Std., Agilent p/n 5190-0483


Column: ZORBAX NH2 4.6x250mm, 5um

Column Temperature: 20oC

Detection: Refractive Index, 35oC

1. cyclohexane 2. o-xylene (dimethylbenzene) 3. dibenzothiophene 4. 9-methyl anthracene

1 2 3 4

System Performance Standard

General Conditions and Schematic of D 6591-06

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September, 2009

ASTM D 6591-06 Calibration Standard A-D, Agilent kit p/n 5190-0482


Column: ZORBAX NH2 4.6x250mm, 5um

Column Temperature: 20oC

Detection: Refractive Index, 35oC

1. cyclohexane 2. o-xylene (1,2-dimethylbenzene) 3. 1-methyl-naphthalene 4. phenanthrene with backflush at ~9 min.

1 2 3 4

Calibration Standards

Analysis of Petrodiesel, overlay of 3 injections

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September, 2009

1. saturates 2. mono-aromatics 3. di-aromatics 4. tri+ aromatics

t= <30 minutes

1 2 3 4

Ultra Low Sulfur Diesel (ULSD), retail pump

Analysis of Petrodiesel, overlay of 3 brands

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September, 2009


t= <30 minutes

1 2 3 4

Ultra Low Sulfur Diesel (ULSD), retail pumps a winter blend, old retained sample summer blends

ASTM D 6591-06 Separation Criteria

The official method clearly describes the appearance and statistical evaluation of method conditions for the new revision Resolution, selectivity, precision and calibration linearity are clearly stated In the following slides we review the performance of the Agilent approach to this method indicates that Agilent meets requirements .

ASTM D 6591-06 Criteria – Column Selection Column Descriptions: 4.6 x 250 mm, stainless steel column packed with 5um ZORBAX NH2 (p/n 880952-708)

. 6.4 Column System—Any stainless steel HPLC column(s) packed with an approved amino-bonded (or polar amino/cyano-bonded) silica stationary phase is suitable…

1. cyclohexane 2. o-xylene (1,2-dimethylbenzene) 3. dibenzothiophene 4. 9-methyl anthracene

1 2 3 4

SPS

1ml/min heptane 20C column temp. 35C RID temp. 20ul SPS no backflush

SPS Separation and Resolution Criteria

.

.

6.4 …provided it meets the resolution requirements laid down in 9.4.3. 9.4.1 Ensure that baseline separation is obtained between all components of the SPS. [without backflush] 9.6 Calculate the backflush time, B, in seconds, using the following equation: B = tA + 0.4(tB – tA)

1. cyclohexane 2. o-xylene (1,2-dimethylbenzene) 3. dibenzothiophene 4. 9-methyl anthracene

1 2 3 4

SPS 1ml/min heptane 20C column temp. 35C RID temp. 20ul SPS backflush 9.4 min.

.

Calculation of Resolution (Cyclohexane to 1,2 dimethylbenzene (o-xylene))

.

9.4.3 Ensure that the resolution between cyclohexane and 1,2 dimethylbenzene is not less than 5.

9.4.3.1 Column Resolution -- Calculate the resolution, R, between cyclohexane and 1,2 dimethylbenzene using the following equation. 2(t2-t1) (difference in retention time) R = ------------------------ 1.699(y1+y2) (averaging of peak widths)

Name R. Time width (hh) Rsln. 1. cyclohexane 3.307 0.059 2. 1,2-dimethylbenzene) 4.477 0.097 8.79

3. dibenzothiophene 8.907 0.186

4. 9-methyl anthracene 18.905 0.282

Linearity (section 9.4: R = >0.999, Intercept <0.01g/100ml) RID peak area vs. Std.Conc., o-xylene

y = 812489.767010x + 963.112364R2 = 0.999995

0

500000

1000000

1500000

2000000

2500000

3000000

3500000

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Conc. (g/100 ml)

RID

Peak A

rea

Series1

Linear (Series1)

. …correlation coefficients all >0.999 (fits are nominally 1), linear fit of the calibration points Intercepts all =<0.005g/100ml

Reproducibility for Retention and Area, Cal. A-D Calibrant A

Analyte R.T. Avg., n=3 R.T. Stdev R.T.RSD% Area Avg., n=3 Area Stdev Area.RSD%

xylene 4.44 0.0005774 0.01% 3.29E+06 755.932096 0.02%

1-Me-naphthalene 5.96 0.001 0.02% 5.76E+06 2299.268 0.04%

phenanthrene 20.14 0.0020817 0.01% 7.12E+05 8351.82533 1.17%

Calibrant B


xylene 4.55 0.0020817 0.05% 8.33E+05 5263.96922 0.63%

1-Me-naphthalene 6.24 0.0041633 0.07% 1.46E+06 14197.7087 0.97%

phenanthrene 20.13 0.0023094 0.01% 3.55E+05 849.500049 0.24%

Calibrant C


xylene 4.63 0.0017321 0.04% 2.06E+05 536.395687 0.26%

1-Me-naphthalene 6.44 0.0036056 0.06% 3.66E+05 1830.77315 0.50%

phenanthrene 20.12 0.0040415 0.02% 8.87E+04 139.006199 0.16%

Calibrant D


xylene 4.67 0.0005774 0.01% 4.03E+04 214.794072 0.53%

1-Me-naphthalene 6.65 0.0020817 0.03% 2.96E+04 334.193512 1.13%

phenanthrene 20.10 0.0025166 0.01% 1.76E+04 176.541808 1.00%

Average RSD% All Runs 0.028% 0.555%

Recommendations for the best configuration

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September, 2009

• Agilent pump, minimum isocratic G1311A • Agilent sampler, minimum G1329A • Agilent thermostatted column compartment (TCC) with 6

port 2 position switching/backflush valve • Agilent RID G1362A • Agilent ChemStation B.04.02 or EZChrom software,

or third party compatible control/data software • Agilent ZORBAX NH2 4.6x250mm 5um column equilibrated

to heptane mobile phase • Agilent calibrants for system performance and calibration • HPLC grade n-heptane, 2-propanol

What to order, for consumables, ASTM D 6591-06

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September, 2009

ASTM D 6591-06 (IP548/06) System Performance Standard (SPS)

Agilent p/n 5190-0483

ASTM D 6591-06 (IP548/06) System Calibration Solutions A-D

Agilent p/n 5190-0482

Column(s):

ZORBAX NH2 4.6x250mm, 5um, Agilent p/n 880952-708

guard cartridge (pk/4) 4.6x12.5mm, 5um, Agilent p/n 820950-908

guard hardware (holder) kit, 4.6mm, Agilent p/n 820888-901

Normal phase pump seals, (pk/2), Agilent p/n 0905-1420

Mobile phase: n-heptane, HPLC grade, minimum 4 Liter or 2.5 Liter bottles, 2-propanol, HPLC grade, 1 Liter (installation, maintenance)

Performance with Selected Samples

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September, 2009

Samples were collected from retail and commercial diesel and biodiesel distribution centers around the Chicago area

One older sample was collected in the cold winter months, all others in recent warm summer months. Fuel blends vary seasonally in this area, with change occurring around early September and April

Sample preparation: Accurately weigh ~1g fuel and dilute to 10ml with

n-heptane. Mix thoroughly and inject 10ul. Calculations: Determine sample concentrations from calibration curves

using 1,2 dimethylbenzene for MAH, 1-methyl-naphthalene for DAH and phenanthrene for Tri+AH. Correct for sample weight and dilution variables.

Conditions: as described in previous slides

Analysis of Petrodiesel, overlay of 3 brands

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September, 2009


t= <30 minutes

1 2 3 4

Ultra Low Sulfur Diesel (ULSD), retail pumps a winter blend, old retained sample summer blends

Analysis of Petrodiesel, n=3, Vendor 1

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September, 2009

MAH DAH Tri+AH

Mobil

Vendor 1, Retail pump, summer

Group Avg., n=3 RSD% MAH 29.26 g/100ml 0.68% DAH 4.74 g/100ml 2.77%

Tri+AH 0.70 g/100ml 6.63%

Analysis of Petrodiesel, n=3 , Vendor 2

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September, 2009

Vendor 2, Retail pump, summer

Marathon

Group Avg., n=3 RSD% MAH 29.38 g/100ml 0.12% DAH 5.10 g/100ml 0.60%

Tri+AH 0.77 g/100ml 1.52%

MAH DAH Tri+AH

Analysis of BioPetrodiesel with ASTM D 6591-06

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September, 2009

Vendor 3, consumer retail pump, summer, dispensing pump labeled “diesel “

Citgo

Amount units Group 21.75 g/100ml MAH

4.12 g/100ml DAH 3.59 g/100ml Tri+AH

erroneous high Tri+AH due to FAME in sample

Analysis of BioPetrodiesel with ASTM D 6591-06

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September, 2009

Vendor 4, commercial biodiesel blend, dispensing pump labeled “diesel”

RR

Amount units Group 26.21 g/100ml MAH

5.12 g/100ml DAH 4.12 g/100ml Tri+AH

erroneous high Tri+AH due to FAME in sample

Analysis of Biodiesel B-11 with Method IP391/07

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September, 2009

RR

Vendor 4, ULSD-based biodiesel blend retail auto/light truck Results are n=3 by IP391/07 method approved for diesel and biodiesel blends

Group Avg., n=3 RSD%

MAH 24.74 g/100ml 5.06% DAH 5.15 g/100ml 3.38%

Tri+AH 0.72 g/100ml 4.58%

FAME resolved

Tri+AH region

ASTM D 6591-06 Observations

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September, 2009

The method retention time stability is very sensitive to column activity, as noted in the official method. This is typical for many normal phase separation methods

Moisture in solvents or samples is problematic and affects column activity

Variable retention is primarily due to moisture and temperature, though good system maintenance is essential

Use of normal phase seals in the pump is very important

Summary ASTM D 6591-06 Status

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September, 2009

Specialized all-Agilent column arrangement meets SPS resolution requirements for cyclohexane and 1,2-dimethylbenzene (o-xylene)

Adding the 6-port valve to the system configuration is required, however it is possible to easily switch between current IP391/07 (no backflush, for biodiesel blends) and ASTM D 6591 (with backflush, no FAME content)

References

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September, 2009

1. IP391/07 / EN12916:2006, Energy Institute, UK

2. Agilent application note 5965-9044E

3. ASTM Methods D6591-06, D6379-04

Appendix and supplemental slides

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September, 2009

…may be used depending on audience and need.

Acknowledgements

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September, 2009

Cynthia – guidance, resources and encouragement

Maggie – continued technical support and for persistence in keeping this development on the road map

Melanie/Georgia/Phil – standards packaging and work with the Ultra Scientific team

Andre – creating the opportunity and motivation

Ultra Scientific – too many to name, once again committed to a successful development with Agilent

Documents

Meeting the Requirements of ASTM D 6591-06 ( … · Meeting the Requirements of ASTM D 6591-06 ( IP548/06 ) with Agilent 1200 LC Systems ... ASTM D 6591-06 Calibration Standard A