Basic Training 4th Annual ICP Conference

4 T H A N N U A L I C P C O N F E R E N C E

SEPTEMBER 25 –26, 2018 CHRI ST IANSBURG, VA

2018 ICP Conference Meeting Agenda

T U E S DAY , S E P T E M B E R 2 5

8:00–8:30 Check In — Coffee 8:30–8:45 Welcome and Introduction

Thomas Kozikowski Chemist, R&D

Basic Needs and Considerations for an ICP Analysis

8:45–9:30

Mike Booth Chemist, Quality Control

ICP Instrument Maintenance and Tuning

9:30–10:15

10:15–10:30 Break

Paul Gaines, Ph.D. CEO, Senior Technical Director

Reliable Measurements Part I: Planning a Trace Analysis

10:30–11:30

11:30–1:00

Lunch

Brian Alexander, PhD. VP Technical Operations

ICP-MS: Limits and Reliable Measurements

1:00–2:00

2:00–2:15

Break

Lesley Owens, Ph.D. Senior Research Chemist

Application of Basic Statistics in Measurement Uncertainty

2:15–3:00

James King Chemist, Technical Manager

ICP Calibration Standards: Design, Handling and Troubleshooting

3:00–3:45

3:45–4:00 Break 4:00–6:00 Tour of Inorganic Ventures and Catered Cocktail Reception

W E D N E S DAY , S E P T E M B E R 2 6

8:00–8:30 Check In — Coffee 8:30–8:45 Morning Remarks

Trace Metals Analysis of Multi-Element Standards by ICP-OES

8:45–9:30

Thomas Kozikowski

ICP-MS: Planning for Tough Samples and Problem Elements

9:30–10:15

Brian Alexander, Ph.D.

10:15–10:30 Break 10:30–11:30

Reliable Measurements Part II: Sample Preparation

Paul Gaines, Ph.D.

11:30–1:00

Lunch

Fundamentals of Method Validation

1:00–1:45

Lesley Owens, Ph.D.

1:45–2:00 Break

Paul Gaines Ph.D. Brian Alexander Ph.D. Lesley Owens Ph.D. Thomas Kozikowski

Roundtable Discussion

2:00–4:00

Mike Booth James King

2018 ICP CONFERENCE SPEAKERS Reliable Measurements: Part I: Planning a Trace Analysis Reliable Measurements: Part II: Sample Preparation Paul Gaines, Ph.D. / CEO, Senior Technical Director

Dr. Paul R. Gaines has four decades of spectroscopic experience. After earning his Ph.D. in chemistry at Iowa State University, Dr. Gaines worked in the laboratories of Exxon Research and Engineering and Union Carbide. Dr. Gaines is also an accomplished web author of many popular guides and papers for fellow spectroscopists.

ICP-MS: Limits and Reliable Measurements ICP-MS: Planning for Tough Samples and Problem Elements Brian Alexander, Ph.D. / Vice President, Technical Operations

Dr. Brian Alexander is an earth scientist specializing in geochemistry. His research has focused on radiogenic isotope and rare earth element studies of natural waters and chemical sediments, as well as trace metal analyses using ICP techniques. A native of southwest Virginia, Brian received his B.Sc. in geology from Virginia Tech, and a M.Sc. and Ph.D. in geochemistry from Penn State and Jacobs University Bremen, respectively.

Application of Basic Statistics in Measurement Uncertainty Fundamentals of Method Validation Lesley Owens, Ph.D. / Senior Research Chemist

Dr. Lesley Owens is an analytical chemist with research specialties including chromium speciation, environmental sample design, elemental spectroscopy, and metal contamination in food products. Dr. Owens graduated from Emory & Henry with a B.S. in Chemistry, and a minor in Mathematics. Owens, a Cunningham Fellow, received her Ph.D. in Analytical Chemistry from Virginia Tech.

ICP Calibration Standards: Design, Handling and Troubleshooting James King, M.Sc. / Chemist, Technical Manager

James King is an inorganic chemist with experience in synthesis and purification. His research has focused on the synthesis and characterization of organometallic compounds to be used as molecular magnets. A native of Hampton, Virginia, James received his undergraduate and graduate degrees from North Carolina A&T State University and Virginia Tech, respectively.

Basic Needs and Considerations for an ICP Analysis Trace Metals Analysis of Multi-Element Standards by ICP-OES Thomas Kozikowski / Chemist, R&D

Thomas Kozikowski is a chemist with expertise in the manufacturing, quality control, technical support, stability, and homogeneity of inorganic metals standards. His experience covers many areas including reagent synthesis and purification, trace metals analysis using ICP techniques, transpiration studies, and container cleanliness. Thomas has a B.S. degree in Chemistry and a B.S. degree in Forensic Science from Virginia Commonwealth University.

ICP Instrument Maintenance and Tuning Michael Booth / Chemist, Quality Control

Mike Booth is a chemist with expertise in quality control and instrumentation. His experience covers areas including ICP-OES, ICP-MS, Ion Chromatography and various titration techniques. Today Mr. Booth is a Quality Control Supervisor at Inorganic Ventures.

4 T H A N N U A L I C P C O N F E R E N C E

BAS IC NE EDS AND CONS I DERAT IONS FOR AN ICP ANALYS I S

inorganicventures.com

Basic Needs & Considerations for an ICP Analysis

Thomas Kozikowski

Key Topics • Tips for preventing environmental contamination • Strategies for different types of samples • Instrument-driven concerns • Defining detection limits • What methods does IV use?

ü Measuring what’s not supposed to be in the solution ü Ignoring what is expected to be in the solution ü Defining instrument detection limits ü Defining real-world detection limits of the sample ü Identifying interferences and method contamination ü Confirming observations by second methods • If possible Overall Goals for TMI Determination

Environmental Contamination

• Container Selection • Pipet Tips • Weigh Boats • Clean Air • Reagent Purity

Container Selection • LDPE , HDPE, PTFE, PFA, PP, Borosilicate Glass • Plastic made from virgin polyethylene is critical • Sample tubes vs. bottles • Leach containers with dilute HNO 3 (1-5% v/v) • High temperature leaching is more effective (50°C)

PP

PP?

Boro Glass

PTFE

HDPE

Containers: More in-depth

Element LDPE HDPE PP PTFE Boro Al 2 * 87 8750 Ba 5000 B 9400 Ca 28 * 25 2800 Fe 150 95 125 Mg 6 11 575 15 125 K 16 3600 Na 42 63 42 90 27500 Zn 125

Values are the ng of impurity per 125mL bottle. * We’ve seen it on occasion.

LDPE

High Temperature Leaching

Element LDPE 20C

LDPE 50C Stationary

LDPE 50C Tumbling

LDPE Chemical Dishwasher 1X

LDPE Chemical Dishwasher 2X

Unleached

Al Cr

2.00 0.03 0.08 1.90

2.20 0.02 0.06 1.50

0.53 0.02 0.06

5

14 30

10

Mn

1 4 1 1

2 8 2

Ni Ag Zn

3.00 2 Values are the ng of impurity per 30mL bottle. The HNO 3 used contains some Al, Cr, and Zn. 2.70

Leaching Observations • Un-leached bottles do contain some metallic impurities • After high temperature leaching, impurities are significantly reduced. • Allowing hot solution to mix within the bottles significantly reduced the amount of impurity left behind • Chemical dishwashers deposited significant amounts of metallic impurities onto the bottle walls. • We believe that the dishwasher contained stainless steel parts.

Other sources of contamination

• Pipet Tips • Same contamination concerns as with sample tubes • Leaching tips if effective • Sterilized tips are for biologicals, not inorganic metals • Weigh Boats • Notorious for dust contamination • Colored boats will have metallic contamination • Virgin or “natural” material is critical • May have surface calcium contamination

How do we leach containers, pipet tips?

5 min Live Demo

Clean Air

• Classed clean rooms help prevent particle contamination • Several criteria to consider to class a clean room • Air changes per minute

• Filter efficiency (ULPAs or HEPAs) • Ceiling type / ceiling panel material • Light fixture type • Wall and floor material • Air return location • Assessed by counting # of particles of specified size

Classed Clean Room Summary

Class 10 ISO4

Class 100 ISO5

Class 1,000 ISO6

Class 10,000 ISO7

Class 100,000 ISO8

Criteria

Air changes/min Filter Coverage Filter Efficiency

8-10

5-8

3

1

0.33 4-5%

90-100%

60-70%

20-30%

7-15%

99.9997% 99.997% 99.997% 99.997%

99.97%

Conventional T- bar grid

Ceiling Type

Al T-bar grid Al T-bar grid Al T-bar grid Conventional T- bar grid

Tear Drop or 2’x4’ cleanroom fixture Low wall on long axis

2’x4’ cleanroom fixture Low wall on perimeter

2’x4’ cleanroom fixture

2’x4’ standard fixture

Light Fixture Type Tear Drop or flow thru

Raised Floor or center

Low wall or ceiling

Air Returns

Low wall

Classed Clean Room Standards

Particle Size

Class 10 ISO4

Class 100 ISO5

Class 1,000 ISO6

Class 10,000 ISO7

Class 100,000 ISO8

≥ 0.1µm 10,000 100,000 1,000,000 ≥ 0.2µm 2,370 237,000 237,000 ≥ 0.3µm 1,020 102,000 102,000 ≥ 0.5µm 352 3,520 35,200

352,000 83,200

3,520,000

≥ 1.0µm ≥ 5.0µm

83

8,320

8,320 2,930

832,000 29,300

293

2,930

• Specifications listed are (Number of Particles / m 3 ). • ISO Class according to ISO 14644-1 cleanroom standards • Class 10, Class 100, etc. are the FED STD 209E equivalent

Reagent Purity

• Clean Acids (HNO 3 • Clean Bases (TEA, NH 4 OH, etc.) • Clean DI Water (ASTM Type 1, 18MΩ) • Particle Filtration (0.3µm or smaller) • Use of reagent blanks , HCl, etc.)

• Critical for blank subtraction to determine true real- world sample impurity levels and detection limits

Key Topics • Tips for preventing environmental contamination • Strategies for different types of samples • Instrument-driven concerns • Defining detection limits • What methods does IV use?

• Pure Samples • Metals or Pure Salts • High Purity Acids and Bases • High Matrix Solutions • Wastewater/Seawater • Food Products • High Matrix Solids • Those that require acid digestion, fusion, or ashing Types of Samples

Pure Samples

• Only one major source of interferences • Depending on concentration level… • May cause signal depression for trace elements • Consider using internal standard • Consider using standard additions method

• Calibration curves that don’t contain the major element at the same concentration will yield a low bias in the trace element results unless corrected.

High Matrix Solutions

• Contains multiple major sources of interferences • Depending on concentration level… • The same concerns for pure samples apply • Interference identification is much more important • Close examination of spectra required • Confirm peak centering and background positions • Background shifting will need to be evaluated • Confirm results on multiple emission lines

High Matrix Solids

• Contains multiple major sources of interferences • The type of digestion will dictate your path • Acid method blanks will be critical • Consider the acid content and the effect that will have on the introduction system parts • High HF needs to be neutralized for quartz systems • HF resistant systems still have certain limitations • Dilution of the sample will increase sample detection limit values

Key Topics • Tips for preventing environmental contamination • Strategies for different types of samples • Instrument-driven concerns • Defining detection limits • What methods does IV use?

Introduction Systems

• Classical Quartz Systems • If HF is used, problems testing B and Si • HF Resistant Systems • If high levels are run, B, Si, and Hg can stick • Peristaltic Pump • Many elements stick to the PVC tubing • Syringe Drive • Peristaltic pump tubing eliminated – much faster washout • More specialized maintenance required

How do we assess memory interferences?

5-10 min Live Demo

100ppm Boron in 0.1% v/v HNO 3 Monitoring Washout on B 208.959nm Rinse w/ 5% HNO 3 Rinse w/ 5% NH 4 OH No obvious difference in washout at first glance.

Washout Example

Monitoring Washout on B 208.959nm Rinse w/ 5% HNO 3 Rinse w/ 5% NH 4 OH 5% HNO 3 doesn’t go to baseline even within 2

minutes. 5% NH 4

OH rinses it out

within 80 seconds.

Washout Considerations

• Boron took much longer to washout when rinsing with the normal 5% v/v HNO 3 . • Washout time was significantly reduced using NH 4 OH. • Time graph only tells part of the story. • A very small peak is still present when viewing in spectra mode. • Time graph can help determine estimated washout. • Verify absence of impurity by viewing the spectra.

Peri-Pump vs. Syringe Drive on MS Blank1 Blank2 Blank2 Sample +4ppb Spike Blank4 Blank5 Blank6 95Mo 6 6 12 1,229 28,443 297 116 77 Peri Pump 95Mo 17 11 13 756 28,443 56 15 15 Syringe Drive 121Sb 17 9 23 437 70,605 1,547 731 443 Peri Pump 121Sb 9 2 4 193 70,605 7 2 11 Syringe Drive 178Hf 36 18 26 5 134,673 134 87 64 Peri Pump 178Hf 0 0 0 4 134,673 11 2 4 Syringe Drive 181Ta 34 55 43 27 461,654 1,467 801 514 Peri Pump 181Ta 20 13 11 7 461,654 87 20 29 Syringe Drive 184W 85 58 58 394 127,417 2,876 1,097 669 Peri Pump 184W 35 26 44 150 127,417 420 226 141 Syringe Drive 209Bi 78 75 50 131 271,275 7,664 2,590 1,323 Peri Pump 209Bi 18 18 31 51 271,275 38 22 24 Syringe Drive 232Th 5 35 12 1,467 349,163 478 173 163 Peri Pump 232Th 15 7 6 15 349,163 26 30 15 Syringe Drive The sample run in this example is 100µg/g Mn.

• Washout of select “sticky” elements after a 4ppb spike containing over 60 elements. • Bi is by far the worst. • PVC tubing is used for peri- pump introduction systems. • Faster washout of elements using syringe drive systems allows us to run more samples free of “memory” interferences. • This results in less maintenance when running TMI samples.

Key Topics • Tips for preventing environmental contamination • Strategies for different types of samples • Instrument-driven concerns • Defining detection limits • What methods does IV use?

Defining Detection Limits

• Limit of Detection (LOD) • Defined as 3 times the standard deviation of the blank • Can be calculated using • peak to peak noise or extrapolation to zero on a calibration curve • Calibration curve should have 3 concentration zones

(low,mid,high) approximately 10x difference in concentration, (ex. 0.1ppm, 1ppm, 10ppm)

Defining Detection Limits

• Limit of Quantification (LOQ) • Defined as 10 times the standard deviation of the blank • Calculated using the same values used for LODs • LOQs will have an uncertainty of approximately 30% at the 95% confidence level • Most impurities found in clean standards are below LOQ, which is one reason why we don’t “certify” trace levels of impurity

Defining Detection Limits

• Detection limit values are run-specific on an ICP • Defined by the background signal noise of a blank

• Depend on the standards used • Depend on instrument conditions • As an instrument ages, the detection limit values will raise over time • You will never have the same levels attainable at the time of instrument setup with a brand new ICP

• Must use dilution factors to translate back to starting material • Most samples must be diluted in order to run at levels that will keep the ICP running • High Na, K, Cs can shut the plasma off • High total dissolved solids (TDS) can clog the nebulizer • Greater than 2000ppm TDS on MS will make internal lenses dirty (requires a service call to clean) Real World Detection Limits

Real World Detection Limits 99.93µg/g Sn Found 452pg/g Pb DL 1pg/g 17,738µg/g Sn Found 80.23ng/g Pb DL 0.18ng/g

1,000,000µg/g Sn Found 4,523ng/g Pb DL 10ng/g Pb

Dilution of sample acceptable for ICP-MS Testing

Sn dissolved in HCl and H 2 O OK on ICP-OES

Sn Shot Starting Material

Key Topics • Tips for preventing environmental contamination • Strategies for different types of samples • Instrument-driven concerns • Defining detection limits • What methods does IV use?

• Calibration curve uses 0ppm, 0.1ppm, & 1.0ppm STDs • 2 x peak-to-peak noise for LOD • We’d rather report more impurity information than to say an element is not detected just to make the purity look better • Quicker calculation: Easy to visually inspect spectra and quickly enter actual count data. Don’t have time to center peaks and correct background point for each element. • Easier when evaluating complex spectra • No internal standards used yet • Would have to allow for different IS elements What IV does on the OES

Our LOD Calculation on OES

1.0ppmMg

1,727,150 cps 0.1ppmMg

Max

Max: 56,523 cps Min: 55,460 cps

Min

56,011 cps BKG

DL Calculation: !.#$$% (#,()(,#*!+*,,!##) (56,523-55,460)(2) = 0.000064ppmMg

Periodic Table of TMI-OES Standards This standard scheme is used for ICP-OES using 2 calibration curves.

What IV does on the MS

• Standard Additions Method • Dilute sample to 100ppm of the major element • Spike half of that sample with 4ppb of standard • 3 Blanks → Sample → Sample+Spike → 3 Blanks • We use 3 times the standard deviation for LOD • Not utilizing spectra but do evaluate washout • Easier to automate the process

Our LOD Calculation on MS Mass Blank1 Blank2 Blank3 Sample +Spike Blank4 Blank5 Blank6 24Mg 237 196 222 352 67,562 222 174 252

LOD Using Blanks 1,2,3 3(21) &.()**+ ,-,/&/ =0.0039ppb LOD Using Blanks 4,5,6 3(39) &.()**+ ,-,/&/ =0.0073ppb

Average Blanks 1,2,3 Blank Corrected +Spike 219 21 219 39 133 67,343 STDEV Blanks 1,2,3 Average Blanks 4,5,6 STDEV Blanks 4,5,6 Blank Corrected Sample

Detected Value for Mg 4.18334 (// ,-,/&/5(// = 0.0083ppb

Periodic Table of TMI Standards This standard scheme is used for ICP-MS using 2 standard addition spike sets.

Technical Support – Available to Everyone Online Resources at inorganicventures.com Customers can visit our website’s

Tech Center, which includes: • Interactive Periodic Table • Sample Preparation Guide • Trace Analysis Guide • ICP Operations Guide • Expert Advice • And much, much more.

4 T H A N N U A L I C P C O N F E R E N C E

ICP INS TRUMENT MAINTENANCE AND TUNING

inorganicventures.com

ICP Instrument Maintenance and Tuning

Mike Booth

Introduction Maintenance • Normal maintenance is essential for your ICP instrument to perform as expected day to day. • Most maintenance is done on the parts of the sample introduction system. • Some instrument maintenance may have to be done by trained field engineers. Tuning • Instrument tuning is performed after your instrument has equilibrated. • There should be a set performance goal that you instrument should reach by tuning. • The inability to complete a performance check my indicate that maintenance is needed.

Introduction Maintenance • Normal maintenance is essential for your ICP instrument to perform as expected day to day. • Most maintenance is done on the parts of the sample introduction system. • Some instrument maintenance may have to be done by trained field engineers. Tuning • Instrument tuning is performed after your instrument has equilibrated. • There should be a set performance goal that you instrument should reach by tuning. • The inability to complete a performance check my indicate that maintenance is needed.

6 Components of Sample Introduction Systems

• Peristaltic Pump or Syringe Drive

• Nebulizer

• Spray Chamber

• Torch

• Cones / Interface

• Tubing

6 Components of Sample Introduction Systems

• Peristaltic Pump or Syringe Drive

• Nebulizer

• Spray Chamber

• Torch

• Cones / Interface

• Tubing

Peristaltic Pumps / Syringe Drives • The method timings for uptake delay, stabilization delay, and rinse will depend on peristaltic pump and/or syringe drive performance

• Peristaltic Pumps

• More common, usually variable speed • Require Peristaltic Pump Tubing • Peristaltic Pumps can cause the sample flow rate to pulsate • Syringe Drives • Usually used with a peristaltic pump and switching valve • Push the sample at a more constant flow rate

Maintenance – Peristaltic Pumps and Syringe Drives • These devices require very little maintenance • Contact the manufacturer if you suspect a malfunctioning peristaltic pump or syringe drive

• Inspect and change peristaltic pump tubing and syringes as needed

6 Components of Sample Introduction Systems

• Peristaltic Pump or Syringe Drive

• Nebulizer

• Spray Chamber

• Torch

• Cones / Interface

• Tubing

Nebulizers • Two widely used types of nebulizers

Concentric • Produces very consistently sized droplets • Some models can easily clog • Newer models are better at handling samples with high total dissolved solids (TDS)

Cross Flow • Generally better at handling high TDS • Argon and sample ports can be fixed or adjustable • Droplets produced are not as consistent

Nebulizers

• Other types of nebulizers • V-Groove • Parallel Path • Direct Injection

• All nebulizers produce an aerosol by mixing your sample with a nebulizer gas

• Nebulizers are usually designed for specific flow rates

• Some nebulizers types can come in glass and plastic • Glass nebulizers have a better nebulization efficiency • Plastic nebulizers are used for samples with HF

Maintenance – Nebulizers (Concentric) • Nebulizers are very delicate – Handle with extreme care • Do not sonicate • The Nebulizer tip is very narrow and may clog from time to time • Never insert anything into the nebulizer • Use an in line filter when running samples with particulate matter

• Clogs can be cleared by forcing water through the nebulizer or back flushing the nebulizer with a special tool • Stubborn clogs may require that the nebulizer be soaked in dilute acid or 25% solution of RBS-25

6 Components of Sample Introduction Systems

• Peristaltic Pump or Syringe Drive

• Nebulizer

• Spray Chamber

• Torch

• Cones / Interface

• Tubing

Spray Chambers • Designed to allow consistently sized droplets to the torch (<8 µm) • Large droplets could overload the plasma causing inconsistent results or cause the plasma to extinguish

• Temperature Control

• Spray chambers are cooled to control water vapor and help prevent oxide interferences • Volatile organics are easier to analyze at lower temperatures

Spray Chambers • Two Styles have remained popular over the years Scott double pass style

• First commercially available spray chamber • Very popular • More nebulizer options

Cyclonic style

• More efficient • Gaining in popularity • Baffled cyclonic spray chambers are often used for organics

Maintenance – Spray Chambers • Flush with DI water frequently

• If instrument performance worsens try soaking in 25% RBS-25 then rinsing with DI water

• Some HF resistant spray chambers may need to be resurfaced after extended use

6 Components of Sample Introduction Systems

• Peristaltic Pump or Syringe Drive

• Nebulizer

• Spray Chamber

• Torch

• Cones / Interface

• Tubing

Torches • It’s important to choose the right torch for your application Full Torch • Easy to use

• Outer tube length, injector length, and injector diameter are fixed

Demountable Torch • Ability to easily change outer tube and injector • Requires more maintenance • More cost effective in most cases

Torches - Injectors • Torch injectors can be interchanged when using a demountable torch

• Quartz – General purpose, No HF • Sapphire/Ceramic – HF Resistant • Platinum – Trace Al Analysis

Torches - Devitrification • All quartz torches will devitrify

• Running samples with high concentrations of total dissolved solids or running at higher temperatures will speed up this process

• Torches with heavy devitrification will need to be replaced • Try a shorter or ceramic outer tube if you have a lot of trouble with devitrification

Maintenance - Torches • Be cautious when sonicating quartz torches

• Flush with DI water

• Soak in dilute acid and 25% RBS-25

• Make sure that the torch is dry before reinstallation

• Organic deposits can be burned off in a muffle furnace (500 C) or dissolved by soaking the torch in a mix of 3:1 concentrated H 2 SO 4 to 30% H 2 O 2 (Piranha solution)

• Broken quartz torches or torches with heavy devitrification may be repairable

6 Components of Sample Introduction Systems

• Peristaltic Pump or Syringe Drive

• Nebulizer

• Spray Chamber

• Torch

• Cones / Interface

• Tubing

Cones / Interface • ICP-MS cones are usually Nickel coated with a Copper core • Platinum tipped cones are also available • Pt cones operate at a higher temperature. This helps reduce buildup from samples with high concentrations of total dissolved solids

• ICP-OES instruments have an interface that needs to be maintained

Maintenance – Cones / Interface • ICP-OES interface should be cleaned daily with dilute acid and water or isopropyl alcohol • Inspect cones frequently • The orifice must retain its shape for the cones to properly function • Clean off buildup with DI water and sonication • The manufacturer’s instrument manual should have sonication instructions • Sonicating with DI water and dilute acid should be OK • Make sure to dry the cones before reinstallation

6 Components of Sample Introduction Systems

• Peristaltic Pump or Syringe Drive

• Nebulizer

• Spray Chamber

• Torch

• Cones / Interface

• Tubing

Tubing • Most connections between introduction system parts are made with tubing • Source the cleanest tubing possible • IV uses PVC and PTFE

• Peristaltic Pump tubing will stretch with use. • Inspect and change frequently

• Most other tubing needs to be inspected and changed when it looks dirty or damaged

Maintenance - Tubing • Periodically change all tubing on your instrument • One clogged piece of tubing could cause a torch to melt, the plasma to extinguish, or cause a large spill

• Make sure that all tubing fittings are tight. • Recommend daily check of fittings

• Pay close attention to the following: • Spray Chamber drain tubing • Torch and nebulizer gas lines • Waste tubing • Rinse station tubing

• Checking the tubing is vital but can be often overlooked - One forgotten connection can melt a torch instantly

Maintenance – General Tips • Make sure to keep a detailed instrument maintenance log • Always inspect all sample introduction parts and connections before turning the instrument on • Rinse the system with dilute acid and DI water before turning the instrument off • Keep an inventory of all your spare sample introduction parts • Make sure to record part numbers • Keep the instrument serial number, instrument manuals, and the phone number to technical support near the instrument • Backup all of your data and have a plan for what to do if your instrument goes down

The manufacturer’s instrument manual should have a recommended maintenance schedule

IV Recommended Maintenance Schedule

Daily

ICP-OES • Clean Interface

ICP-MS • Inspect Cones • Inspect Torch • Inspect Spray Chamber • Inspect Nebulizer • Inspect/Replace Peristaltic Pump Tubing • Inspect Tubing Connections • Acquire Performance Report • Inspect Other Intro System Parts

Necessary maintenance will vary based on instrument make, model, and sample matrix

• Clean/Replace Torch • Clean Spray Chamber • Clean Nebulizer • Replace Peristaltic Pump Tubing • Inspect Tubing Connections • Acquire Performance Report • Inspect Other Intro System Parts

Weekly

Monthly

ICP-OES • Perform Wavelength Calibration • Inspect All Tubing

ICP-MS • Clean Cones

ICP-MS • Replace All Tubing • Check Filters and Chiller • Check Vacuum Pump

ICP-OES • Replace All Tubing • Check Filters and Chiller

• Clean/Replace Torch • Clean Spray Chamber • Clean Nebulizer • Perform Mass Calibration • Inspect All Tubing

Introduction Maintenance • Normal maintenance is essential for your ICP instrument to perform as expected day to day. • Most maintenance is done on the parts of the sample introduction system. • Some instrument maintenance may have to be done by trained field engineers. Tuning • Instrument tuning is performed after your instrument has equilibrated. • There should be a set performance goal that you instrument should reach by tuning. • The inability to complete a performance check my indicate that maintenance is needed.

ICP Instrument Tuning – What are you looking for? ICP-OES • High Intensity • Low RSDs ICP-MS • High Intensity • Low RSDs • Low Oxides • Low Doubly Charged Species

ICP Instrument Tuning – What to adjust? ICP-OES • High Intensity • Torch Alignment • Confirm Gas Flows • Low RSDs • Confirm Method Timings • Check Intro System Connections • Confirm Gas Flows ICP-MS • High Intensity • Low RSDs • Low Oxides

• Low Doubly Charged Species

ICP Instrument Tuning – What to adjust? ICP-OES • High Intensity • Torch Alignment • Confirm Gas Flows • Low RSDs • Confirm Method Timings • Check Intro System Connections • Confirm Gas Flows ICP-MS • High Intensity • Torch Alignment • Confirm Gas Flows • Lens Tuning • Low RSDs • Confirm Method Timings • Check Intro System Connections • Confirm Gas Flows • Low Oxides • Nebulizer Gas Flow • Spray Chamber Temperature • Low Doubly Charged Species • Lens Tuning

ICP-MS Instrument Tuning Auto-Tuning

• The Auto-Tune will usually work best to tune the instrument for the entire mass range. • Depending on your instrument software this can be done as part of the start up routine.

Manual Tuning • This can be done much more quickly than the auto-tune once you are familiar with your instrument. • You can tune for specific mass ranges.

Remember: You only have to tune to meet your performance checks

Technical Support – Available to Everyone Online Resources at inorganicventures.com

• Customers can visit our website’s Tech Center , which includes: – Interactive Periodic Table – Sample Preparation Guide

– Trace Analysis Guide – ICP Operations Guide – Expert Advice – And much, much more.

4 T H A N N U A L I C P C O N F E R E N C E

RE L IABLE MEASUREMENT S

inorganicventures.com

Reliable Measurements A Guidebook for Trace Analysts

Paul Gaines, PhD

This society makes many decisions based upon chemical measurements. These decisions have legal, medical, environmental, and commercial impact upon each of us.

Trained Analysts

Reliable Results

Accurate CRMs

Accurate Procedures

Overview

1.1 - 1.14 Laying the Foundation (What is Trace Analysis?, Stages of a Trace Analysis, Training, Recommended References)

2.1 - 2.9 Planning the Project ( Defining The Problem, Detection Limits and Uncertainties, Constructing the Sampling Plan)

3.1 - 3.16 Sampling and Sub-sampling (Sampling Publications, Developing the Sampling Plan, Constructing a Sampling Program, Different Approaches to Sampling, Sub-sampling, Determination of Sampling and Sub-Sampling Errors, Contamination Issues During Sampling)

4.1 - 4.5 An Introduction to Sample Preparation (Preliminary Issues, Selecting a Sample Preparation Method)

Overview

5.1 - 5.13 Container Material Properties (Materials; Borosilicate, Glass, Porcelain, Quartz, Platinum, Graphite, Plastics; The Purity and Cleaning of Plastics)

6.1 - 6.6 Container Transpiration (Initial Transpiration Study, Additional Transpiration Studies, Summary of Findings)

7.1 - 7.14 Stability of Elements at ppb Concentration Levels (Adsorption, ppb Stability Study, Summary of Findings)

8.1- 8.19 Environmental Contamination ( Reducing Environmental Contamination, Avoiding Environmental Contamination)

Overview

9.1- 9.18 Contamination From Reagents (High Purity Water, Storage of High Purity Water, High Purity Acids, Other Reagents)

10.1-10.12 Contamination From the Analyst and Apparatus (Contamination From the Analyst, Common Contaminants, Tips for the Analyst, Apparatus Contamination, A Closer Look at Quartz, Apparatus Tips)

11.1-11.7 Acid Digestions of Inorganic Samples ( Nitric Acid Digestions, Facts About Nitric Acid)

12.1-12.3 Acid Digestions of Organic Samples (Acid Digestions of Organic Samples)

Overview

13.1-13.8 Sample Preparation by Fusion (Useful Fusions for Trace Analysts, Lithium Carbonate Fusions, Sample Preparation Procedure)

14.1- 14.11 Ashing (Ashing Techniques, Advantages of Ashing, Disadvantages of Ashing, Examples of Ashing Procedures)

15.1-15.15 ICP-OES Measurement (Line Selection, Sensitivity, Precision, Spectral Interferences, Example of a Method, Matrix Effects)

Overview

16.1 - 16.22 ICP-MS Measurement (ICP-MS References, Resolution, Interference, Isobaric Interference, Polyatomic Interferences, Doubly Charged Ion Interferences, Matrix Effects, Space Charge Effects, Salt Buildup, Quantitative Analysis Measurement Techniques, External Calibration using Calibration, Standard Additions, Isotope Dilution) 17.1 - 17.30 Method Validation (Purpose of Method Validation, References, The Validation Process, Confirm Basic Performance Criteria, Robustness, Collaborative and Cooperative Testing)

1:1 Laying the Foundation

What is Trace Analysis? Some analysts refer to trace analysis as a measurement below one ppm (μg/g) while others use the term to describe an analyte concentration low enough to cause difficulty. This difficulty may be caused by the sample size or the matrix (i.e. - the concentration of the analyte of interest relative to the matrix or the sample size causes difficulty for the analyst). Most trace analysts using ICP-OES / ICP-MS prefer the latter definition. Regardless of which definition you prefer, most analyses that require a measurement using ICP-OES or ICP-MS fall within the category of trace analysis.

1:2 Laying the Founda@on

Stages of a Trace Analysis

A. Planning - Prepare a plan that considers the objective. Planning should begin with a discussion between the analyst and the initiator during which all possible problems are defined. The analyst is responsible for method selection or development.

B. Sample Collection and Storage - Ideally the analyst is involved in this stage, but if not, the analyst should be informed of the sampling procedure at the very least. Sample representation and contamination issues must be considered.

C. Sample Preparation - Contamination issues are a major concern during this stage, but not the only concern .

1:3 Laying the Foundation

D. Sample Measurement - The major concerns during this stage are:

• Availability of Certified Reference Materials for method validation, plus stable and accurate calibration standards, interference standards, and quality control standards.

• Achieving the required precision. It serves no purpose in acquiring a precision that has been reduced to less than one-third of the sampling error. In situations where the sampling error is small and the highest level of precision is required, the analyst faces a difficult task in acquiring precision equivalent to classical wet chemical techniques.

• Obtaining the required sensitivity and determining the detection limit of the measurement.

1:4 Laying the Foundation

D. Sample Measurement - (CONT.)

• Overcoming interferences using ICP-OES that include matrix differences between standards and samples; spectral interferences (i.e. - direct spectral overlap, wing overlap, interference with background point); chemical enhancement of atom lines by high matrix element compositions (axial view); and drift due to nebulizer plugging, changes in sample argon, power supply instability, or room temperature changes. • Overcoming interferences using ICP-MS that include matrix differences between standards and samples; mass-discrimination effects; isobaric interferences; detector dead-time; and drift due to nebulizer plugging, changes in sample argon, power supply instability, or room temperature changes.

• Calculating and Reporting the Data - Working with error budgets and calculating the uncertainty is the trickiest part of this stage.

1:5 Laying the Foundation

Training Trace analysis is extremely difficult. All too often, samples submitted as "routine" actually require highly skilled analytical chemists using complex chemical treatments and expensive state-of-the-art equipment. Today, many analysts do not have the proper training, nor do they have access to a more experienced colleague that could offer assistance. The availability of sensitive "push- button" instrumentation is ever increasing. Laboratory supervisors should not assume that an analyst is trained to perform trace analysis if the instrument's instruction manual was the only source of training. Education should be provided for the analyst. Furthermore, job experience and training records should be kept and reviewed on an annual basis.

1:6 Laying the Foundation

Recommended References For some applications, a search of the literature is required. Larger companies typically have a library and often a staff of chemists trained to conduct literature searches. For smaller companies without these facilities, the Internet is of great value in finding technical information.

A search of the scientific literature, complete with the ability to download or order specific papers, is available through the CAS Document Service at stneasy@cas.org. Visit our links section for additional links to EPA, AOAC, and other published methods.

1:7 Laying the Founda2on

General References:

CRC Handbook of Chemistry and Physics; Lide, D. R., Ed.; CRC Press: Boca Raton, FL.

Encyclopedia of Analytical Science; Townshend, A., Ed.; Academic Press: New York, 1995, Vols. 1-10.

IV's Analytical Periodic Table; Information on elemental compatibility, stability, sample preparation, preferred lines and spectral interferences for ICP-OES and ICP- MS; Inorganic Ventures / IV Labs: 2001-2002.

1:8 Laying the Foundation

Sampling:

Sampling and Sample Preparation; Stoeppler, M., Ed.; Springer Publishing: New York, 1994.

Crosby, N. T.; Patel, I. General Principles of Good Sampling Practice; The Royal Society of Chemistry: Cambridge, U.K., 1995.

1:9 Laying the Foundation

Sample Preparation:

Gorsuch, T.T. The Destruction of Organic Matter; Pergamon Press: Elmsford, NY, 1970.

Introduction to Microwave Sample Preparation, Theory and Practice; Kingston, H. M., Jassie, L. B., Eds.; American Chemical Society: Washington D.C., 1988.

A Handbook of Decomposition Methods in Analytical Chemistry; Bock, Rudolf, Ed.; Halsted Press, Div. Wiley & Sons: New York, 1979; translated by Ian L. Marr.

Mizuike, A. Enrichment Techniques for Inorganic Trace Analysis; Springer-Verlag: New York - 1983.

1:10 Laying the Founda2on

Trace Analysis:

Trace Analysis: A Structured Approach to Obtaining Reliable Results; Prichard, E., MacKay, G. M., Points, J., Eds.; The Royal Society of Chemistry: Cambridge, U.K., 1996.

Guidelines for Achieving Quality in Trace Analysis; Sargent, M., Mackay, G., Eds.; The Royal Society of Chemistry: Cambridge, U.K., 1995

1:11 Laying the Foundation

Environmental Analysis:

Smith, Roy-Keith Handbook of Environmental Analysis; Genium Publishing: U.S.A., 1994.

Berger, W.; McCarty, H.; Smith, Roy-Keith Environmental Laboratory Data Evaluation; Genium Publishing: U.S.A., 1996.

1:12 Laying the Foundation

Quality Assurance & Statistical Technique:

Taylor, J. K., Quality Assurance of Chemical Measurements; Lewis Publishers: Chelsea, MI, 1987. Mark, H.; Workman, J. Statistics in Spectroscopy; Academia Press: San Diego, CA, 1991. Taylor, J. K. Statistical Techniques for Data Analysis; Lewis Publishers: Chelsea, MI, 1990. Swartz, M. E.; Krull, I. S. Analytical Method Development and Validation; Marcel Dekker: New York, 1997. Accreditation and Quality Assurance in Analytical Chemistry; Günzler, H., Ed.; Springer-Verlag: New York, 1994. Good Laboratory Practice Standards; Garner, W.Y., Barge, M. S., Ussary, J. P., Eds.; American Chemical Society: Washington D.C., 1992.

1:13 Laying the Founda2on

ICP-MS References:

Plasma Source Mass Spectrometry - Developments and Applications; Holland, G., Tanner, S. D., Eds.; The Royal Society of Chemistry: Cambridge, U.K., 1997.

Inductively Coupled Plasma Mass Spectrometry; Mantaser, A., Ed.; Wiley-VCH: New York, 1998.

Taylor, H. E. Inductively Coupled Plasma Mass-Spectrometry, Practices and Techniques; Academic Press: New York, 2001.

1:14 Laying the Foundation

ICP-OES References:

Inductively Coupled Plasmas in Analytical Atomic Spectrometry; Montaser, A., Golighty, D. W., Eds.; VCH Publishers: New York, 1992.

Thompson, M.; Walsh, J. N. A Handbook of Inductively Coupled Plasma Spectrometry; Blackie: London, U.K., 1983.

Developments in Atomic Plasma Spectrochemical Analysis; Barnes, R. M., Ed.; Heyden: London, U.K., 1981.

2:1 Planning the project

Overview

The first stage of a trace analysis is planning the project. This chapter discusses the process of planning, which involves defining the problem and assessing the technical requirements needed to solve the problem. Without careful planning, achieving reliable results becomes a game of chance.

Analytical projects fall into categories of non-routine, semi-routine, and routine:

• Non-routine - a project in which a validated method does not exist and little is known about the sample. • Semi-routine - a project in which something significant can be stated about the sample and the method of analysis. • Routine - a project in which the sample is chemically known and a validated method is available.

2:2 Planning the project

Overview (cont.)

This section assumes that the chemist will be analyzing samples that fall into one or more of the previous categories. Before the planning process can begin, the analyst must examine the following:

• The need for sampling and sub-sampling • Reagent quality • Sample preparation • Measurement • QA/QC • Reporting requirements

2:3 Planning the project

Defining the Problem

A discussion between the initiator and the analyst must occur, where questions are asked by both parties. The intent is to define the exact nature of the problem, why analytical work is needed, and how the results will be used following the completion of the project. Method validation requirements should also be addressed. These requirements can include either the availability of a certified reference material, or that of another validated technique -- one that is based largely on different principles. The problem's definition is further refined by asking other questions: What is it that you want to accomplish? What is the purpose? What is the current situation or state of affairs? What is taking place that you need to understand, prevent, or improve? What decisions will be made based upon the data?

When the answers to these questions have been determined, the analyst is in a position to begin planning the analytical process.

2:4 Planning the project

Detection Limits and Uncertainty

The analyst should know the detection limits for all analytes at several possible wavelengths. Typically, these measurements are obtained during the establishment of the analytical instrument's capabilities.

Modern axial view ICP-OES and ICP-MS instruments are likely to have detection limits under normal sample introduction modes that will meet or exceed the requirements. It is best to not rely upon the limits published by the manufacturer. In addition, the detection limits will be a function of the sample matrix, in both a physical and spectral sense. A key point involves the analytical blank. Due to numerous contamination issues, the analytical blank often determines the detection limit capabilities. It is best for the analyst to be conservative when noting the detection limits, making sure not to quote capabilities calculated from published data or determinations made under "ideal" conditions. For the less common elements, an estimate of the "real" detection limit would be a factor several times higher than the limit determined under ideal conditions. Thus, elements like Na, Mg, Ca, Fe, Cr, Cu, Zn, Si, Al, Cl, and S may have a detection limit that is significantly larger than expected, due to the analytical blank.

2:5 Planning the project

Detection Limits and Uncertainty (cont.)

The uncertainty of an analytical measurement is not limited to the measurement precision of the instrument. Rather, it is a statistical sum of the random and systematic errors that are encountered throughout the entire analytical process. The uncertainty is a combination of errors from sampling, storage, weight and volume manipulations, preparation, calibration, and measurement, during which contamination issues play a major role in trace determinations. The sampling error can be a major source of uncertainty. In many cases, an estimate of the sampling error can be impossible to judge. The initiator should be aware of this fact. In reality, the uncertainty of a trace measurement will not be known until the project is completed. The accuracy of this value will be only as good as the effort made to identify and measure all of the errors encountered during the entire analytical process. If measurements are being made between 3-5 times the detection limit for the less common elements, then an excellent uncertainty would be ± 30-70%.

2:6 Planning the project

Constructing the Plan

After the problem is defined, the planning process can begin. Analytical text books explain that you must consider the sample collection, sample storage, sample preparation, measurement, and reporting, along with any QA/QC requirements. With so many considerations, where should you start?

Start by examining the following basic information: • The analyte(s) of interest.

• The required detection limit(s). • The uncertainty requirement(s).

• The chemical composition (matrix) of the sample. • The quantity, availability, and history of the sample.

2:7 Planning the project

Constructing the Plan (cont.)

Much of the previous list can be determined based on information gathered while defining the problem. In most cases, analytical resources are available in-house to address the problem.

For example: • The basic information listed previously is sufficient to determine whether publications or information is available in your reference library. Always start with a search of the literature. • The identity and detection limit requirement of each analyte indicates the analyte measurement technique(s) required and the amount of sample required. • The uncertainty requirement indicates the number of measurements, assuming there is sufficient sample available. • The chemical composition of the sample, together with the identity of the analyte(s), indicates possible sample preparation routes.

2:8 Planning the project

Constructing the Plan (cont.)

• The identity of the analyte(s), together with the detection limit requirement(s), indicates the degree that contamination issues should be considered. This determines the need for

analytical blanks and special apparatus or a clean area / room. • The sample composition indicates potential interference issues.

• The sample composition or type indicates the uncertainty to be expected form the sample collection and/or the need to develop a sampling procedure and to determine sampling uncertainty. For example, the sample may be the only "world's supply", negating the need for a sampling procedure. • The estimated sampling uncertainty can be used to define the analytical measurement precision (i.e. -- reducing the analytical error to less than one third of the sampling error serves no purpose).

2:9 Planning the project

Constructing the Plan (cont.)

The basic information can provide the analyst with potential analytical measurement technique(s), suspected interferences, contamination issues, and the number of sample measurements required per determination (measurement refers to a complete analysis including sampling, preparation, instrumental analysis and reporting the final result and uncertainty). At this stage of the planning process, the analyst can determine if a certified reference material (CRM) should be obtained for method validation. In addition, the chemist can approximate the need for analytical reagents and apparatus and/or calibration standards.

Lastly, estimate the time and cost of the project and base your initial approach on these estimates. Remember, there is always the possibility that more than one iteration may be required before an acceptable approach can be developed.