7890a – an essential partner for the trace analysis of ... · analysis of complex...

7890A – An Essential Partner for the Trace Analysis of Complex MatricesAnalysis of Complex Matrices

• Backflush – An Essential Tool for Complex Matricesp– QuickSwap option for MS transferline– Purged Ultimate Union Backflush option for the GC– Backflush App Notes

Backflush: Many Advantages for GC/MS Analysis of Complex Samples (‘Dirty Matrices’)of Complex Samples ( Dirty Matrices )

• Provides more consistent GC retention times

• Provides better, more consistent MS spectra through a sample sequence

Reduces chemical noise that may increase during a sequence of– Reduces chemical noise that may increase during a sequence of samples due to small carryover of matrix from sample to sample

– Higher quality quantitation (no increase in interfering ions during analysis sequence)

• Reduces contamination (and cleaning frequency) for the source

R d l i ti ( l d )• Reduces analysis time (more samples per day)

• Increases lifetime of analytical column

Analytical Reality of GC/MS/MS Methods

• With the selectivity of MS/MS, the user cannot see the matrix

– Hundreds and even thousands of matrix peaks are “invisible” in MS/MS mode

• MS/MS users want the LOWEST detection limits, so they inject even more sample into the GC/MS/MS system with PTV in LVI modep y

– “Invisible” matrix peaks are even MORE intense

• Many late eluting peaks are not “chromatographically ideal” and leave a residue th h t th lthroughout the column

– This residue increases with each subsequent injection

– Matrix carryover increases as more samples are injectedy p j

• Heavy matrix contaminates the source faster and sensitivity is LOST!

Analytical Reality of GC/MS/MS Methods

GC/MS/MS needs backflush as much or more than GC/MS to avoid “invisible” problems:invisible problems:

source contaminationloss of sensitivity

And to avoid the visible problems:changing retention timesg g

Without Backflush: A Serious Problem

Abundance

4.4e+074.6e+07

A: TIC: lettuce_blank.D\data.ms

B: TIC: lettuce_blank3.D\data.ms

After only 3 samples, the background is significantly

3e+073.2e+073.4e+073.6e+073.8e+07

4e+074.2e+074.4e 07

Data provided by MSD user in Almeria, Spain

g g yhigher (increase chemical noise is every spectrum)

1.8e+072e+07

2.2e+072.4e+072.6e+072.8e+07

3e+07B

A

400000060000008000000

1e+071.2e+071.4e+071.6e+07

Overlay of two chromatograms of a blank extract injected BEFORE (A) and AFTER (B) three injections without backflush

4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00020000004000000

Time


Without Backflush: Changes in Retention Time

Abundance

4.4e+074.6e+07



Highly retained matrix is altering the column selectivity and changing

3e+073.2e+073.4e+073.6e+073.8e+07

4e+074.2e+074.4e 07


selectivity and changing the retention time

1.8e+072e+07

2.2e+072.4e+072.6e+072.8e+07

3e+07B

A

400000060000008000000

1e+071.2e+071.4e+071.6e+07


4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00020000004000000

Time


Without Backflush: Increased Background

Abundance

4.4e+074.6e+07



Increased background due to carryover of concentrated matrix

3e+073.2e+073.4e+073.6e+073.8e+07

4e+074.2e+074.4e 07


concentrated matrix

1.8e+072e+07

2.2e+072.4e+072.6e+072.8e+07

3e+07B

A

400000060000008000000

1e+071.2e+071.4e+071.6e+07


4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00020000004000000

Time


With Backflush: No Increased Background (Less Spectral Noise) and Consistent Retention Times

4 2e+074.4e+074.6e+07

Abundance

TIC: lettuce_10_ppb.D\data.msTIC: lettuce_100_ppb.D\data.ms

Stable retention times and baseline less3 07

3.2e+073.4e+073.6e+073.8e+07

4e+074.2e+07 TIC: lettuce_5_ppb.D\data.ms

Data provided by user in Almeria, Spain

and baseline . . . less chemical noise

2e+072.2e+072.4e+072.6e+072.8e+07

3e+07

80000001e+07

1.2e+071.4e+071.6e+071.8e+07

O l f th h t f l tt t t ith 2 i f b k fl h

4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.000

200000040000006000000

Time

Overlay of three chromatograms of lettuce extract run with 2 min of back flush

Agilent’s 7890A CFT Advantage for Backflush

• Multiple ways to setup the backflush using Capillary Flow Technologies

– QuickSwap

– Deans Switch

– 2-Way Splitter with Makeup

– 3-Way Splitter with Makeup

Th P d Ulti t U i– The new Purged Ultimate Union

New Purged Ultimate Union: Analysis ModePressure / Split/Splitless Z mL/min very low flow; set against

Vent

Flow Controller

Capillary Flow

p pInjection Port

Z ml/min

y ; gcolumn backpressure, not short restrictor as with QuickSwap

Capillary Flow Technology Device

5975C MSDEI mode

7890A GC

Y+Z ml/minY Z ml/min

P dY ml/min

Purged UltimateUnion

15-m HP-5ms (0.25mm id x0.25um)

15-m HP-5ms (0.25mm id x0.25um)

Column 1 and 2 could be different phases and different dimensionsAvailable Oct’08

Purged Ultimate Union: Backflush ModePressure / Split/Splitless

Vent

Flow Controller

7890A GC

p pInjection Port

Capillary FlowDecrease inlet pressure during

5975C MSDEI mode

7890A GC Capillary Flow Technology Device

pressure during backflush

15-m HP-5ms (0.25mm id x0.25um)

15-m HP-5ms (0.25mm id x0.25um)

Backflush (BF) with the Purged Ultimate Union

Sample - no backflush

9.00 9.50 10.00 10.50 11.00 11.50 12.00

Sample - with backflush

a b

a = begin backflush (last peak exits column 1)

b = increase flow 4 mL/min

Sample with backflush

9.00 9.50 10.00 10.50 11.00 11.50 12.00

a b b = increase flow 4 mL/min

Solvent blank - no backflush9.00 9.50 10.00 10.50 11.00 11.50 12.00

Comparison of Backflush Configurations

QuickSwap (QS) Purged Ultimate Union30 (0 092 *) 1

Backflush (BF) Pressure (psi)

BF flow (mL/min)

1 column vol (min)

MDS flow (mL/min)

BF flow (mL/min)

1 column vol (min)

MSD flow (mL/min)

Time savings

(N x)

30 m column; restrictor (0.092mm*) Two 15 m columns

10.0 0.3 3.82 1.5 0.6 0.94 0.9 4.120.0 0.7 1.89 2.9 1.5 0.47 1.8 4.030.0 1.3 1.28 4.8 2.6 0.32 3.0 4.0

4 f t &* smallest restrictor =>

40.0 2.1 0.98 7.2 4.1 0.25 4.5 3.9

4x faster & lower flow!

best QS case

T=300°C; head pressure =0.5psi

Sensitivity Without and With Purged Ultimate Union• Because there is no flow dilution (or less), there is “no” sensitivity lost …( ), y

16000

17000

S (ht) = 12700 (±4.4%)S (area) = 8900 (±1.5%)

S/N = 1180 (±10%)

S (ht) = 12600 (±3.4%)S (area) = 8600 (±3.6%)

S/N = 1540 (±10%)

No PCT With PCT

11000

12000

13000

14000

15000

PCT 30-m

S/N = 1180 (±10%)S/N = 1540 (±10%)

6000

7000

8000

9000

10000

1000

2000

3000

4000

5000

5.005.055.105.155.205.255.305.355.405.455.505.555.605.655.705.755.805.850

>

Signal is maintained (Detectability) but Noise increases (from the additional EPC)

Purged Ultimate Union Example: Lipid Peroxidation Products in BloodLipid Peroxidation Products in Blood 4-hydroxy-2,3-nonenal (HNE), an indicator of oxidative stress, and its metabolite, 1,4-dihydroxynonene (DHN)

PCI with NH3

Note late eluting peakseluting peaks

App Note 5989-9359EN

Loss of Response without Backflush Lipid Peroxidation Products in BloodLipid Peroxidation Products in Blood

with backflushwith backflush

without backflush

App Note 5989-9359EN

Purged Ultimate Union for GC/MSNew, simple CFT technology for backflush

• Vent-less injector and column maintenance (first column)• Improved backflush

– 1/4 the time and/or lower pressure– Compatible with diffusion pump MSD

• Less loss of sensitivity (less flow added = less dilution)y ( )• Option of different phase/dimension for each column • Less complex

– No restrictor to choose as with QuickSwap– Simple GC configuration (existing supplies)– Setpoints calculated by GCy– Pressure pulsed injections OK– Constant flow mode easy!!

Newest References for Backflush (Pg 1 of 2 )

• 5989-8664EN Capillary Flow Technology for GC/MS: a Simple Tee Configuration for Analysis at tracea Simple Tee Configuration for Analysis at trace Concentrations with Rapid Backflushing for Matrix Elimination (June 08, Prest)( , )

• 5989-9359EN Capillary Flow Technology for GC/MS: Efficacy of the Simple Tee Configuration for RobustEfficacy of the Simple Tee Configuration for Robust Analysis Using Rapid Backflushing for Matrix Elimination (Aug 08, Prest, Foucault, and Aubut)

References for Backflush (Pg 2 of 2 )

• 5989-6460EN Analysis of Suspected Flavor and Fragrance Allergens in Cosmetics Using the 7890A GC and Capillary Column Backflush (March 2007)Backflush (March 2007)

• 5989-6066EN Rapid Forensic Toxicology Screening Using an Agilent 7890A/NPD/5975C/DRS GC/MSD System (Jan 2007)5989 6095EN Direct Injection of Fish Oil for the GC ECD Analysis• 5989-6095EN Direct Injection of Fish Oil for the GC-ECD Analysis of PCBs: Results Using a Dean Switch with Backflushing (Jan 2007)

• 5989 6018EN Improving Productivity and Extending Column Life• 5989-6018EN Improving Productivity and Extending Column Life with Backflush (Dec 2006)

• 5989-5111EN Simplified Backflush Using Agilent 6890 GC Post Run Command (June 2006)Run Command (June 2006)

• 5989-1716EN New Tools for Rapid Pesticide Analysis in High Matrix Samples (October 2004)

7890a – an essential partner for the trace analysis of ... · analysis of complex...

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