Automated Sample Preparation for Ion Chromatography · Automated Sample Preparation for Ion Chromatography ... Sample Preparation On Line ... Sample Preparation): Automation to prepare

Automated Sample Preparation for

Ion Chromatography

Joachim Weiss, Ph.D.

Thermo Fisher Scientific GmbH, Dreieich, Germany

Proprietary & Confidential2 Dionex Confidential

• Retention times too short

• Poor peak efficiency

• Poor resolution

• Poor reproducibility

• Irregular baseline

• Interference with analyte signal

• Quantitative dynamic range too narrow

• Electrochemical detector electrode fouling

Reasons for Sample Preparation

Proprietary & Confidential3 Dionex ConfidentialDionex ConfidentialDionex Confidential

Off-line and In-line Sample Preparation Tools

IonChromatography

Off-Line Sample Preparation

On-Line Sample Preparation

OnGuard

ASE

AutoTrace

AutoDilution

Concentration

RFIC-ESP

Electrolytic Water Purifier

CR-TC

AutoNeutralization

Matrix Elimination

AutoPrep

Filtration

Filtration

Filter Caps

InLine Filters

CRD 200/300

Combustion Bomb

Combustion IC

InGuard™


New Publications

• Application notes, Application Briefs

• AB 106 − Trace analysis on ICS-2100

• AN 220 − Inorganic ions in water insoluble pharmaceuticals

• AN 244 − Phosphate using “heart cut” technique, 10-valve and concentrator

• TN 81 − AutoDilution, partial loop injection

• TN 83 − AutoDilution, vial-to-vial dilution

• TN 84 − AutoDilution, large loop/ small loop (updated)

• LC/GC application book page − Chloride removal using InGuard Ag and Na

• InGuard™ manual


AUTODILUTION


Thermo Scientific Dionex AutoDilution

• Suitable for IC and HPLC

• No additonal hardware required – low cost

• Based on the Chromeleon AutoDilution license

• Easy to install – no service engineer necessary

• Wizard for choosing re-injection conditions

• Easy to set up

• Determination is based on peak area, peak height, amount

(any Chromeleon variable)

• Dilution/injection volume is defined in a new Program File

• New sequence is only created for re-injected samples

• Different tasks with conditional programs can be defined

• Customized solutions for different budgets

• Partial loop re-injection (AS-AP)

• True dilution in a new sample vial (ASAP)

• Small/large injection loop (AS-DV or Dionex ICS with 10-port valve)


AutoDilution: Large Loop / Small LoopConditional Injection

0.0

4.0

0 20

Sulfate Calibration Function

Are

a

(µS

*min

)

Concentration (mg/L)

Highest Calibration Standard

Analytical Result

0 12

0.0

2.5Wastewater

AS18, 4 mm,

33 mmol/L KOH

µS

Minutes

Fluoride

Chlo

ride

Nitrate

Sulfate

Phosphate

Analytical result is outside the calibrated range

Sample will be re-injected


0.0

1.4

0

Sulfate Calibration Function

Are

a

(µS

*min

)Concentration (mg/L)

7

Highest Standard

Analyical result

0 12

0.0

2.5Wastewater re-injected, small loop

AS18, 4 mm, 33 mmol/L KOH

[µS]

Minutes

Chloride

Nitrate

Sulfate

The analytical result now lies well within the calibrated range



Chromeleon adds lines for the sample re-injections to the same

or a different sequence:



PRE-CONCENTRATION AND IN-LINE CALIBRATION


IonPac UTAC-LP2, UTAC-ULP2 and UTAC-XLP2 Concentrator Columns

• Improved back pressure resilience, no pulse damper required

• Compatible with polyacrylic acid application in the power

generating industry

• Ultra-clean (no bleed of sulfate) concentrator columns providing

reliable quantification

• Available in 3 formats

• UTAC-LP2 (4 x 35 mm)

• UTAC-ULP2 (5 x 23 mm)

• UTAC-XLP2 (6 x 16 mm)

• Replacement for UTAC 1 columns


IonPac AC-ER Concentrator Column

• Very low dead volume concentrator based on the UTAC 2 resin

• Each injection only adds 75 μL of sample matrix into the eluant regardless

of the sample volume

• 266 injections can be performed before the eluant needs to be replaced,

regardless of the actual amount of sample loaded onto the concentrator

• Enables matrix elimination

• Solvents can be directly injected onto the AC-ER and then flushed off

before injection into the RFIC-ER system

• Enables a host of new applications with RFIC-ER systems

• Analysis of bromate to 5 ppb in drinking water

• Analysis of common anions in ethanol

Expands application capabilities of RFIC-ER


RFIC-ESP™

• RFIC-ESP™ (Reagent Free Ion Chromatography – Electrolytic

Sample Preparation): Automation to prepare samples on-line with an

electrolytic water purifier

• Electrolytic water purifier

• Enables use of ICS-2100 for

automated trace analysis

• Column effluent is passed through

the water purifier and is used to

transfer samples and standards from

loops to a concentrator column


Why RFIC-ESP™

• Only one pump needed (lower cost)

• Simplifies trace analysis

• Very low backgrounds

• Very low detection limits (<5 ppt) with less pre-concentration

volume

• Automated sample calibration and concentration

• Fewer errors, improved reliability, lower labor costs


Electrolytic Water Polisher

2 H2O + 2e-

2OH-+ H2H2O 2H

++ ½ O2 + 2e

-

CathodeAnode

Anion

Exchange

Membrane

Cation

Exchange

Membrane

OH-H+

H+OH-H2O

H2O H2O

Na+ Cl-Cl-Na+

UPW


RFIC-ESP: How Does the Water Polisher Work?

• Continuous electrolytic purification of aqueous input

• Point-of-use operation for automated preparation of standards

and samples

• Single-digit parts-per-trillion or better quality output water

• Cleaner input water to IC results in better MDL’s and system

performance

• No contamination of samples during pre-concentration

• Blank levels 10x lower than reported values


Water Quality after Polisher Treatment

0 5 10 15 20 26

–0.2

1.0

µS

F-

Minutes

20 mL pre-concentration of UPW from polisher

Less than 5 ppt fluoride, acetate and formate (from fluoropolymer tubing)

Very low and consistent chloride, nitrate, and sulfate blank!


RFIC-ESP™ Configuration

ASRS

EluentGenerator

LP Concentrator

Guard Column CD Cell

Eluent

Suppressed Eluent

Pure Water

Electrolytic

Polisher

Standard or Sample

(10 µL)

Large volume

Autosampler

310

58

Electrolytic

Polisher


Standard Calibration Procedure

• Use incremental volume of fixed loop to increase

standard concentration (X1, X2…..X10)

• Calibrate IC dilution factor from known standards

(e.g., 1:1000 of 1000 µg/L)

• Use response from fixed loop (1000X) to

determine the required pre-concentration volume

• Use the resulted pre-concentration volume to

validate and qualify the calibration procedure


Calibration with RFIC-ESP™ (Cal 1x)

ASRS

EluentGenerator

Guard Column CD-Cell

EluentSuppressed

Eluent

Pure Water

Standard



Calibration with RFIC-ESP™ (Cal 5x)

ASRS

EluentGenerator


EluentSuppressed

Eluent

Pure Water

Standard

Repeat Load/Inject 5 times

Use same

flushing volume



RFIC-ESP™ – Automated Calibration


RFIC-ESP™ : Anions at ng/L Levels in UPW

Peak Name Amount (ng/L)

F 24.033

Cl 22.307

NO2 42.532

0 5 10 15 20 26

0

1

µS

Minutes

F Cl NO2


RFIC-ESP™ : Cations at ng/L Levels in UPW

Peak Name Amount (ng/L)

Li 11.511

Na 28.403

NH4 13.499

K 15.197

Mg 7.729

Ca 11.238

0 5 10 15 20 26

0

0.5

µS

Minutes

Li Na NH4 KMg Ca


RFIC-ESP™ – Detection Limits

Estimated Detection Limits (3xSD)

Fluoride 0.6-0.9 ppt

Chloride 1.0-2.4 ppt

Nitrite 2.3-3.2 ppt

Bromide 3.3-5.8 ppt

Sulfate 2.3-3.2 ppt

Nitrate 2.7-4.4 ppt

Orthophosphate 3.0-3.8 ppt


RFIC-ESP™ – Summary

• RFIC-ESP offers a simple method to perform ng/L analyses

• Online standard addition can be used for automated system

calibration

• Target markets: power generating and semiconductor industries

• Ease of installation and operation

• Simple matrix removal techniques can easily be incorporated

into the concept


MATRIX ELIMINATION

Proprietary & Confidential28 Dionex ConfidentialDionex Confidential

Matrix Elimination − Commonly Used for Sample Clean-up in Ion Chromatography

• Mechanism

• Solid phase does not retain the analytes; matrix interferences

are bound to the phase while the analyte flows through

• Instances where analyte is collected and matrix washed away

• Applications

• Impurity removal

• Desalting

• pH adjustment

• Chemistry

• Ion exchange

• Precipitation

• Neutralization, pH adjustment


“2-D” Phosphate Analysis − Fun with Valves

11

0

8

6

5

2

7

3

Analytical

Column

Guard

Column

Suppressor

Detector

9

4

L

C

LS

W

P

Auto-

Sampler

PUMPWaste

Waste

Courtesy of Rolf Maurer, Thermo Fisher Scientific Switzerland

“Waste” stream is directed via 10-port valve to concentrator,

then re-injected


“2-D” Phosphate Analysis − Fun with Valves(AN 244)

0

0

10

µS

Phosphate Phosphate

Minutes 23

0 23

0

1

µS

Minutes

Phosphate

Phosphate

Valve switch to concentrator

Valve switch to waste

0 23

0

1

µS

Minutes

Phosphate

Phosphate

Valve switch to concentrator

Valve switch to waste 0

1

µS

Auxiliary valve enables “heart cut”, improving LOD

Courtesy of Rolf Maurer, Thermo Fisher Scientific Switzerland


ONGUARD CARTRIDGES


OnGuard™ Sample Pre-treatment Phase Chemistries

Phase Functionality Retention

Mechanism

Application

A Anion exchange resin

Bicarbonate form

Ion exchange Remove anions, increase pH

Ag Sulfonated resin

Silver form

Ion exchange/ Precipitation Remove halides

Ba Sulfonated resin

Barium form

Ion exchange/ Precipitation Remove sulfate

H Sulfonated resin

Acid form

Ion exchange Remove cations, reduce pH

M Iminodiacetate

Ammonium form

Chelation Remove transition metals

Na Sulfonated resin

Sodium form

Ion exchange Remove cations, no pH change

P Polyvinylpyrrolidone H-Bonding/ Complexation Remove phenols, azo dyes, humic acids

RP Polydivinylbenzene Adsorption Remove neutral hydrophobics


OnGuard™ Application Examples

• Iodate in sodium hydroxide OnGuard H: Neutralization

• Cations in sulfuric acid OnGuard A: Neutralization

• Organic acids (maleate, fumarate,

acetate, and lactate) in cider and vinegar OnGuard P: Remove organics

• Anions in respiratory drugs OnGuard H: Remove basic drugs

• Anions in a quaternary amine solution OnGuard Na: Remove alkyl

ammonium

ions

• Iodide in urine OnGuard RP: Remove organics

• Bromate in hypochlorite solution OnGuard Ag: Remove chloride

• Carbohydrates in instant coffee OnGuard P: Remove phenolics


INGUARD CARTRIDGES


InGuard™ Cartridges

• New cartridges designed for automated matrix elimination procedures

• Several versions available for various applications:

Cartridge Functional group(s) Binding mode Example applications

Ag Ag+ form sulfonate Ion Exchange Removal of halides

Na Na+ form sulfonate Ion Exchange Removal of cations

H H+ form sulfonate Ion Exchange Removal of cations,

pH adjustment

HRP Hydrophilic

divinylbenzene

Adsorption, π-π

bonding

Removal of hydrophobic species,

azo- and cyano-containing species

Na/HRP Na+ form sulfonate,

Hydrophilic

Ion exchange

(Na)

and Adsorption

Remove Ca2+ (Na) and lipids (HRP)

from dairy products



• Cartridges are of high capacity

• In-line approach − sample volume per cycle equals injection volume

• Small amount loaded onto cartridge increases effective capacity to

many samples per cartridge

• Reduced sample processing time, labor and cost

50% Na / 50% HRPNa/HRP

2 g resinHRP

5 to 5.5 mequivNa

5 to 5.5 mequivH

5 to 5.5 mequivAg

Cartridge CapacityCartridge Type



• Cartridges are all PEEK, 9 mm by 24 mm form factor

• Designed for low back pressure − less than 50 psi at 2 mL/min

• Enables sample loading with an autosampler

• Two or more cartridges can be operated in series- for example, Ag and Na

L

CL

S

W

P

Waste

SuppressorAnalytical

Column

Guard

Column

Detector

Auto-

Sampler

InGuard

Cartridge

Concentrator

Column

Pump



Cartridge capacity example − 1% sodium chloride sample

• 1% NaCl contains 170 mequiv per liter of sodium

• 100 µL injection contains 0.017 mequiv of sodium

• Cartridge capacity is 5 mequiv, so…

• Each InGuard Ag cartridge has a nominal capacity of 292 samples

1% NaCl = 10 g/L NaCl

10 g/L NaCl is 10 g / 58.45 g/mol = 0.171 mol

1% NaCl is 0.171 mol/L

100 µL injected is 0.0001 L

0.0001 L* 0.171 mol/L = 0.0000171 mol, 1.71*10-5 mol.

NaCl is 1 equivalent Na / mol,

so each sample is 1.71*10-5 equivalent of Na per injection

5*10-2 equivalents per cartridge / 1.71*10-5 equivalents per sample

= 292 samples / cartridge



Application example:

Anion analysis in 1.6% NaCl, treat with InGuard Ag followed by InGuard Na

1

Minutes0 40

0

7

µS

1

2

3 45

1.6% NaCl w/o InGuard

1.6% NaCl blank without InGuard

1.6% NaCl with InGuard Ag and Na

Water blank with InGuard

Std of 2 mg/L nitrite, sulfate, and nitrate in 1.6% NaCl using InGuard

Peaks: mg/L (in standard)

1 Chloride

2 Nitrite 2

3 Carbonate

4 Nitrate 2

5 Sulfate 2

Column: IonPac AS15 + guard, 4 mm

Eluent: 23 mmol/L KOH (EG)

Flow rate: 1 mL/min

Sample prep: InGuard Ag and Na cartridges

Inj. volume: 100 µL

Detection: Suppressed conductivity



Application example:

1.6% NaCl, plumbing schematic

4

6

12

3

5

PumpWaste

Suppressor

Analytical

Column

Guard

Column

Detector

L

C

LS

W

P

Loading

Pump

Auto-

Sampler

Waste

InGuard

Ag

Trap

Column

Concentrator

Column

InGuard

Na


RFIC-ESP Configuration for Matrix Elimination

^

ASRS

EluentGenerator

LP Concentrator


Eluent

Suppressed Eluent

Pure Water

Electrolytic

Polisher

Autosampler

310

58

Waste or

EWP (2)

InGuard


Caustic Wastewater (Bayer Liquor Plant)

Sample

Concentrator

Guard

Separator

EWP

CD

3

5

7

9

1

P Waste

RP Cartridge

Eluent(RFIC EG)

1]

2]

3]

[4

[5

[6

L

L

C S

W

S

RS

Matrix: Aluminium hydroxide

Calcium and magnesium

Transition metals

Organics


Plating Bath Wastewater

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

0.0

2.5

5.0

7.5

10.0

µS

Minutes

Chl

orid

e

Ort

hoph

osph

ite

Sul

fate

Ort

hoph

osph

ate

Column: AS18 + guard, 4 mm

Eluent: KOH gradient (EG)

Detection: Suppressed conductivity,

External water mode

Flow rate: 1 mL/min

Inj. volume: 10 µL

Sample: Nickel plating bath

1:1000 dilution and filter

Analytes: 0.28% chloride

1.47% orthophosphite

13.3% sulfate

0.04% orthophosphate

Concentrator

Separator

Sample

GuardEWP

CD

3

5

7

9

1

P Waste

RP Cartridge

Eluent(RFIC EG)

1]

2]

3]

[4

[5

[6

L

L

C S

W

SRS


Carbonate Removal

Sample

Concentrator

Guard

Separator

EWP

CD

3

5

7

9

1

P Waste

RP Cartridge

Eluent(RFIC EG)

1]

2]

3]

[4

[5

[6

L

L

C S

W

SRS

CRD 0 1 2 3 4 5 6 7 8 9 10 11 12 13

2.5

5.0

9.0AS18 Control

µS

Minutes

0 1 2 3 4 5 6 7 8 9 10 11 12 13

2.5

5.0

9.0AS18 Recycle Tap water

µS

Minutes

Carbonate


Adsorption Removal

0 5 10 15 20

0.0

0.2

0.4

0.6

0.8

1.0

µS

Minutes

Concentration: 14.00 mM

50.00

Sample

Concentrator

Guard

Separator

EWP

CD

3

5

7

9

1

P Waste

RP Cartridge

Eluent(RFIC EG)

1]

2]

3]

[4

[5

[6

L

L

C S

W

SRS

Column: IonPac AS15 + guard, 4mm

Eluent: 15 mmol/L KOH (EG) for

0-20 min, 60 mmol/L for

20-40 min

Detection: Suppressed conductivity,

External water mode

Flow rate: 1mL/min

Inj. volume: 25 µL

Sample: Pasteurized milk

1:10 dilution and filter

Analytes: 0.2 mg/L nitrite (spiked)

2.5 mg/L nitrate



• Ordering Information (box of 4 cartridges each):

• Ag+ P/N 074038

• H+ P/N 074037

• Na+ P/N 074036

• HRP P/N 074034

• Na+/ HRP P/N 074035


FILTRATION


In-line Filtration with Cartridges and Valves

• Multiple configurations available

• Filter in sample line before injection valve

• In-line on high pressure side

• Dual filters and 10-port valve with back flush pump

• High capacity, high volume filter stack of 35 µm,7 m, 0.45 µm filters

• Low capacity, low volume filter frit, 0.5 m

• Advantages

• Entire sample is filtered − no sample loss

• Small sample volume loaded onto filter maximizes capacity

• Filter back flush minimizes carryover and extends filter lifetime


In-line Filtration: Low Pressure or High Pressure

Suppressor

AnalyticalColumn

GuardColumn

Detector

Auto-

Sampler

L

C

LS

W

P

Pump

Waste

AXP

Waste

1

10

98

6

54

2

7

3

1

10

98

6

54

2

7

3

AXP

Suppressor

AnalyticalColumn

GuardColumn

Detector

Waste

LC

LS

W

P

Pump

Auto-

Sampler

Waste

Filter on the high-pressure side Filter on the low-pressure side


Auxiliary Valves: ICS-2100 and ICS-5000+


Plumbing, Dual In-line Filter with Back Flush

1

10

9

8

6

54

2

7

3

L

C

LS

W

P

AXP

Pump

Auto-

Sampler

Suppressor

Analytical

Column

Guard

Column

Detector

Waste

Waste


AUTOMATED SAMPLE PREPARATION KITS


Automated Sample Preparation Kits

• In-line filter cartridge and 0.5 µm frits P/N 074505

• Replacement 0.5 µm frits P/N 074506

• In-line filter (dual) with back flush P/N 074507

• Hydrophobic organics removal, NG1 P/N 074508

• Hydrophobic organics removal, NG1 (2 mm) P/N 074509

• Humic acids removal, InGuard HRP P/N 074510

• Halides removal, InGuard Ag and Na P/N 074511

• Metals and organics removal, InGuard Na/HRP P/N 074512


Automated Sample Preparation Kits – Example

• Humic acid removal, InGuard HRP w/ concentrator column, P/N 074510

• InGuard HRP (box of 4 cartridges)

• UTAC-ULP1 concentrator column

• ATC-HC trap column (purify loading water)

• Bolt, double cone ferrule (5)

• Double cone ferrules (pack of 10)

• 0.01 inch PEEK tubing (black), 5 feet

• Basic instructions and plumbing diagrams

• Necessary, not included in kit:

• Sample loading

• AXP pump, bottle and cable OR

• EWP for sample loading

• 10-port valve


Summary

• Many new applications notes, briefs and more to come!

• New InGuard inline matrix elimination cartridges

• New concentrator columns

• New automated sample preparation kits

56 Proprietary & Confidential

Thank you for your kind attention!

Documents

Automated Sample Preparation for Ion Chromatography · Automated Sample Preparation for Ion Chromatography ... Sample Preparation On Line ... Sample Preparation): Automation to prepare