Category Archives: Chromatography Quiz

Amino Acid Analysis, Chromatography Quiz, Michael Pickering, Ninhydrin, Trione, Uncategorized

Chromatography Quiz #16

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Chromatography Quiz #15 Results

We would like to congratulate our grand prize winners of our last newsletter’s Amino Acids Analysis Chromatography Quiz: Tom Schneider from Suffolk County Water Authority, Jim Balk from DHHS Public Health Environmental Laboratory, and Narjes Ghafoori from LA County Environmental Toxicology Laboratory!

They have each won and will shortly be receiving: a $100 gift card for Best Buy, which can be used online or in the store!!!

We would like to thank all of you for your submissions!

The correct answer for the Amino Acids troubleshooting chromatogram: the baseline noise was caused by a dirty flow cell. As we have seen through several Chromatography Quizzes, baseline noise can have a variety of causes, both mechanical and chemical. In this chromatogram, the noise we are seeing is not regular or repeatable, steering us away from the HPLC pump, a trapped bubble, or the back-pressure regulator.

To learn more about baseline noise, please review Maria’s article entitled “The Art of Noise” (http://pickeringlabs-retentiontimes.com/?p=58) from a previous newsletter.

Thank you!

Pickering Labs

Chromatography Quiz #16:

We are doing something a little bit different with this quiz! Identify what’s wrong with the picture below and win a prize! Simply email your answer as well as your full contact information to Rebecca at rlsmith@pickeringlabs.com by July 1st, 2014 in order to win. You will receive email confirmation that your submission has been received. The answer to the quiz and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in your submission).

A blast from the past: What is wrong with this picture?!

As you can probably tell from the photo, we’ve dug into Michael’s past for our quiz this quarter! Look carefully and see if you can figure out what’s wrong with this picture! If you have any questions, please feel free to email Rebecca at rlsmith@pickeringlabs.com for further guidance.

Michael_Trione Ad

Amino Acid Analysis, Chromatography Quiz

Chromatograpy Quiz No. 15

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Chromatography Quiz #14 Results

We would like to congratulate our grand prize winners of our last newsletter’s Carbamate/Glyphosate Crossword Puzzle Chromatography Quiz: Jim Balk from DHHS Public Health Environmental Laboratory, Amanda Comando and Dan Raphaely from SCWA, June Black from the Pennsylvania Department of Environmental Protection, Narjes Ghafoori from LA County Environmental Toxicology Laboratory, Helene Lachance from Shur-Gain Nutreco, Holger Franz from Thermo Fisher Scientific, Matthew Hartz from Underwriters Laboratories, Hossein Hajipour from Texas Department of State Health Services, and Daniel Durham from Georgia Department of Natural Resources!!!

rum cake picThey have each won and will shortly be receiving: a Tortuga To Go Suitcase Gift Pack from tortugarumcakes.com!  This “vacation in a box” includes three rum cakes and an 8oz package of coffee, shipped directly from the Cayman Islands!

We would like to thank all of you for your submissions!

The correct answers for the Carbamate/Glyphosate crossword puzzle:

Across:

1. Pickering column protection system: GARD
6. Heated or Ambient: REACTOR
10. ChlorAC buffer for sample ________: PRESERVATION
11. Over-pressure ________ valve: RELIEF
12. Internal Standard: BDMC
13. Faulty check valves yield a noisy ________: BASELINE
14. Solution to late, broad Glyphosate and AMPA peaks: RESTORE

Down:

1. Glyphosate oxidized by hypochlorite: GLYCINE
2. Pickering Catalog number 3700-2000: THIOFLUOR
3. Reagent one: HYDROLYSIS
4. Fourth peak: METHOMYL
5. Glyphosate herbicide: ROUNDUP
7. _______ detection: FLUORESCENCE
8. o-phthaladehyde: OPA
9. Gradient, water and _______ : METHANOL

Thank you!
Pickering Labs

Chromatography Quiz #15:

Identify the error made when running the Amino Acids chromatogram below and win a prize!  Simply email your answer as well as your full contact information to Rebecca at rlsmith@pickeringlabs.com by May 1, 2014 in order to win.  You will receive email confirmation that your submission has been received.  The answer to the quiz and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission).

Amino Acid Analysis – Baseline Noise

Pinnacle PCX post-column instrument is being used, in a traditional HPLC setup as recommended by Pickering Labs.  The chromatogram is expanded to show the baseline noise.  The quiz question is: what is causing this problem?

Post-column conditions for amino acid analysis:
Reagent 1: Trione
Reactor 1: 130 °C, 0.5 mL
Reagent flow rate: 0.3 mL/min

Detection: UV-Vis Detector, 570 nm for primary amino acids, 440 nm for secondary amino acids

Problem Chromatogram:

problem chromatogram
Please use our website to view any reference Amino Acid chromatogram – the problem for this quiz is not application-specific, so any of our AAA methods could be applicable.  If you have any questions, please don’t hesitate to email Rebecca at rlsmith@pickeringlabs.com.

carbamate, Chromatography Quiz, glyphosate

Chromatography Quiz No.14

Chromatography Quiz #13 Results

We would like to congratulate our grand prize winners of our last newsletter’s Carbamate Analysis Chromatography Quiz: Irene Taylor from Orange County Utilities, Jim Balk from DHHS Public Health Environmental Laboratory, Narjes Ghafoori from LA County Environmental Toxicology Laboratory, Helene Lachance from Shur-Gain Nutreco, and Jamie Palmer and Matthew Hartz from Underwriters Laboratories!!!

laser chess 1They have each won and will be receiving: a Laser Board Game from laser chess 2Sharper Image!  (This strategy-based board game is similar to chess and features an 80-square Egyptian themed grid.  The goal is to protect your game pieces while eliminating your opponent’s by bouncing eye-safe lasers at them through the maze of mirrors you’ve constructed.)

We would like to thank all of you for your submissions!

The correct answer for the modified Carbamate chromatogram: Reagent #2 (CB910, OPA, and Thiofluor) was partially oxidized.  The peak heights of Carbaryl and 1-Naphthol have significant diagnostic importance in regard to the OPA reagent system. Since 1-Naphthol naturally fluoresces, we can eliminate the fluorescence detector as the problem.  Though smaller peak sizes can reflect problems with Reagent #1, since the Carbaryl peak is full-sized, we can deduce that hydrolysis has occurred (Carbaryl naturally fluoresces after hydrolysis).

Particularly astute observation yields additional details about our troubleshooting chromatogram – slightly shifting retention times towards the end of the run could indicate a problem with HPLC hardware, such as a proportioning valve.

Thank you!

Pickering Labs

 Chromatography Quiz #14:

Complete the cross word puzzle below and win a prize!  Simply email your answer (copy of completed puzzle or list answers with clues) as well as your full contact information to Rebecca at rlsmith@pickeringlabs.com by December 15, 2013 in order to win.  You will receive email confirmation that your submission has been received.  The answer to the puzzle and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission).

Carbamate/Glyphosate Analysis: Cross Word Puzzle

crossword

carbamate, Chromatography Quiz, pickering laboratories, post-column derivatization

Chromatography Quiz No. 13

Chromatography Quiz #12 Results

We would like to congratulate our grand prize winners of our last newsletter’s Amino Acid Analysis Chromatography Quiz: Luiz Paulo Mousinho from Chemetric in Brazil, Helene Lachance from Shur-Gain Nutreco in Canada, and Narjes Ghafoori from the LA County Environmental Toxicology Laboratory!!!

They have each won and will be receiving: a $100 gift card from Amazon.com!  We would like to thank all of you for your submissions.

The correct answer for the modified Amino Acids chromatogram: the back pressure regulator on the outlet of the detector stopped functioning properly.  This was indeed another hardware troubleshooting quiz!  The pattern of noise seen in the customer’s baseline is characteristic to this problem, and a new back pressure regulator eliminated the noise.

Thank you!
Pickering Labs

Chromatography Quiz #13:
Identify the error made when running the Carbamate chromatogram below and win a prize!  Simply email your answer as well as your full contact information to Rebecca at rlsmith@pickeringlabs.com by August 30, 2013 in order to win.  You will receive email confirmation that your submission has been received.  The troubleshooting answer and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission).

Carbamate Analysis for US EPA Method 531.1

Pickering Standard: 1700-0063 Carbamate Test Mixture, 2.5 µg/mL, 10 µL injection

Pickering Column: 1846250 Carbamate Column, C18, 4.6 x 250 mm

Normal Operating Conditions: (for reference only, condition changes may be reflected in chromatogram)

Column Temperature: 42 °C

Flow rate: 1 mL/min

Eluent Gradient:

TIME

WATER

MeOH %

0

85

15

1

85

15

44

25

75

44.1

0

100

49

0

100

49.1

85

15

57

85

15

 

Post-column conditions:

Reagent 1: Hydrolysis reagent CB130

Reagent 2: 100 mg of OPA, 2 g Thiofluor™ in 950 mL of CB910

Reactor 1: 100 °C, 0.5 mL

Reactor 2: ambient. 0.1 mL

Reagent flow rates: 0.3 mL/min

Detection: Fluorometer ex 330 nm, em 465 nm

Troubleshooting Chromatogram:

Troubleshooting chromatogram_CarbamateReference Chromatogram:

Reference chromatogram_Carbamate

Amino Acid Analysis, Chromatography Quiz

Chromatograpy Quiz No. 12

Chromatography Quiz #11 Results

We would like to congratulate all six grand prize winners of our last newsletter’s Glyphosate Analysis Chromatography Quiz: Thomas Schneider from Suffolk County Water Authority, Hélène Lachance from Shur-Gain Nutreco in Canada, Jim Balk from DHHS Public Health Environmental Laboratory, Tom Phillips from Maryland Department of Agriculture, Matthew Hartz from Underwriters Laboratories, and Narjes Ghafoori from the LA County Environmental Toxicology Laboratory!!!

tea They have each won and will be receiving: a wooden chest of premium and specialty teas by Silkenty Tea (purchased from GiftTree.com)!  We would like to thank all of you for your submissions.

 

 

The correct answer for the modified Glyphosate chromatogram: Iron contamination has been introduced into the system and has fouled the column, resulting in poor peak shape and a retention time shift in AMPA.  If the problem worsened, the peak shapes would continue to deteriorate and eventually the Glyphosate peak could vanish completely.

The recommended action would be to reverse-flush the column with RESTORE™. The presence of polyvalent metal ions (especially iron) can rapidly lead to serious degradation of column performance.

Thank you!

Pickering Labs

Chromatography Quiz #12:

Identify the error made when running the Amino Acids chromatogram below and win a prize!  Simply email your answer as well as your full contact information to Rebecca at rlsmith@pickeringlabs.com by April 30, 2013 in order to win.  You will receive email confirmation that your submission has been received.  The troubleshooting answer and winner congratulations will be published in the next issue (to remain anonymous, please notify Rebecca in submission).

Amino Acid Analysis – Baseline Noise

Pinnacle PCX post-column instrument is being used, in a traditional HPLC setup as recommended by Pickering Labs.  The chromatogram is a close-up of a customer’s reoccurring baseline noise, and the quiz question is: what is causing the noise?

Post-column conditions for amino acid analysis:

Reagent 1: Trione

Reactor 1: 130 °C, 0.5 mL

Reagent flow rate: 0.3 mL/min

Detection:

UV-Vis Detector:  570 nm for primary amino acids,  440 nm for secondary amino acids

Please use our website to view any reference Amino Acid chromatogram – this quiz is not application-specific per say, and as such any of our AAA methods could be applicable.  If you have any questions, please don’t hesitate to email Rebecca at rlsmith@pickeringlabs.com.

bad baseline chromatogram quiz 12

 

 

Chromatography Quiz, glyphosate

Chromatography Quiz No. 11

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Chromatography Quiz #10 Results

We would like to congratulate the grand prize winners of our last newsletter’s Amino Acids Analysis (hardware problem) Chromatography Quiz: Hélène Lachance from Shur-Gain Nutreco in Canada, and Narjes Ghafoori from the LA County Environmental Toxicology Laboratory!!!

They have each won and will be receiving: a Google/Asus Nexus 7 Tablet!  We would like to thank all of you for your submissions.

The correct answer for the modified Amino Acids chromatogram: There was a bubble trapped in the LC Pump head.  Similar noisy baselines could be caused by any of the following: bad pump seals, bad check valves, scratched or damaged pump pistons, faulty pulse dampener, or problems with connections to the pump.  Post-column systems containing reciprocating pumps can also cause noisy pulsations in the baseline, and the frequency of the sine waves should be evaluated to determine which pump is causing the noise. 

This problem can also be caused by dirty reagents or eluents, however in this case the pulsations would be accompanied by the elevation of the background signal. 

Thank you!
Pickering Labs

Chromatography Quiz #11:

Identify the error made when running the Glyphosate chromatogram below and win a prize!  Simply email your answer as well as your full contact information to Rebecca at rlsmith@pickeringlabs.com by January 31, 2013 in order to win.  You will receive email confirmation that your submission has been received.  The troubleshooting answer and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission). 

Glyphosate Analysis for US EPA Method 547

Pickering Standard: Glyphosate Test Mixture 1700-0080, 2.5 ug/mL, 10 µL injection 

Pickering Column: 1954150 Cation-exchange Column for Glyphosate Analysis,
4 x 150 mm

Normal Operating Conditions: (for reference only, condition changes may be reflected in chromatogram)

Column Temperature: 55 °C

Flow rate: 0.4 mL/min

Eluent Gradient:

TIME K200 RG019 %
0 100 0
15 100 0
15.1 0 100
17 0 100
17.1 100 0
27 100 0

Post-column conditions for pesticide analysis:

Reagent 1: Oxidizing reagent – 100uL of 5% Sodium Hypochlorite in 950mL of GA116

Reagent 2: 100 mg of OPA, 2 g Thiofluor™ in 950 mL of GA104

Reactor 1: 36 °C, 0.5 mL

Reactor 2: ambient. 0.1 mL

Reagent flow rates: 0.3 mL/min

Detection: Fluorometer ex 330 nm, em 465 nm

 

Note: A special thanks to Michael Pickering for the suggestion and for providing the “old school” chromatograms (notice the chart reader font on the retention times)!

                                    

 

Amino Acid Analysis, baseline noise, Chromatography Quiz

Chromatography Quiz #10

Chromatography Quiz #9 Results

We would like to congratulate the grand prize winner of our last newsletter’s Amino Acids Analysis Chromatography Quiz: Jim Balk from the State of Nebraska DHHS Public Health Environmental Laboratory!!!

He has won, and will shortly be receiving: an Amazon.com gift card!  Additionally, all participants will be receiving a gift card from Amazon.com!  Again, we would like to thank all of you for your submissions.  

The correct answer for the modified Amino Acids chromatogram: the sample has been prepared at the wrong pH.  The Aspartic Acid peak is misshapen and splitting, a clear indication that the sample is not sufficiently acidic. After checking the sample pH to determine the required correction, Li220 can be used to adjust to the appropriate pH. 

Thank you! 

Pickering Labs

Chromatography Quiz #10:

Identify the error made when running the Amino Acids chromatogram below and win a prize!  Simply email your answer as well as your full contact information to Rebecca at rlsmith@pickeringlabs.comby August 31st in order to win.  You will receive email confirmation that your submission has been received.  The troubleshooting answer and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission). 

Hint: Quiz #8 was so popular that we’ve decided to run another hardware problem!

Amino Acid Analysis of Protein Hydrolysate

Pickering Standard: 012506H Protein Hydrolysate Standard, in 0.2 N Sodium citrate buffer pH 2.20, 0.25 µmole/mL, 10 µL injection

Pickering Column: 1193250 Standard Sodium Cation-exchange Column, 3.0 x 250 mm

Normal Operating Conditions: (for reference only, condition changes may be reflected in chromatogram)

Column Temperature: 48 °C

Flow rate: 0.3 mL/min

Eluant Gradient:

TIME
Na328 %
Na740 %
RG0011 %
0
100
0
0
10
100
0
0
32
0
100
0
56
0
100
0
56.1
0
0
100
58
0
0
100
58.1
100
0
0
70
100
0
0

Post-column conditions for amino acid analysis:
Reagent 1: Trione
Reactor 1: 130 °C, 0.5 mL
Reagent flow rate: 0.3 mL/min

Detection: UV-Vis Detector, 570 nm for primary amino acids,  440 nm for secondary amino acids

Chromatogram to Troubleshoot:
Full Chromatogram:

Enlarged View:
Further Enlarged View:

Reference Chromatogram: Click HERE and scroll down to PN 1193250