Category Archives: Chromatography Quiz

Chromatography Quiz, glyphosate

Chromatography Quiz Number 3

Reminder: Please resubmit your answers to last quarter’s Amino Acid Chromatography Quiz by June 1st to be eligible for a prize. You can find that quiz located on our Blog at Chromatography Quiz #2.

Chromatography Quiz #3

Identify the error made when running the Glyphosate chromatogram below and win a prize! Simply email your answer and your full contact information to Rebecca at rlsmith@pickeringlabs.com by July 1st in order to win. You will receive email confirmation when your submission is received, and 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
Normal Operating Conditions: (for reference only, changes may be reflected in chromatogram)

Customer’s Glyphosate Standard: 25 ppb, 100 µL injection

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

Column Temperature: 55 °C
Flow rate: 0.4 mL/min

Eluent Gradient:
Glyphosate Analysis for US EPA Method 547

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

Post-column conditions for pesticide analysis

 
Amino Acid Analysis, Chromatography, Chromatography Quiz, Physiological Fluids, Post-column

Chromatography Quiz No. 2

Congratulations to the winners of our last newsletter’s Chromatography Quiz: Matthew Hartz, Jamie Palmer, and Keena Njoroge from Underwriters Laboratories, Sudheer Reddy from Chemtex, and Becky Canela from Environmental Laboratory Services!

two dozen irresistible cookiesThey’ve each won, and will shortly be receiving from Gifttree.com, two dozen irresistible cookies in five flavors: White Chocolate Hazelnut, Snickerdoodle, Peanut Butter, Oatmeal Raisin, and Chocolate Chip.

The correct answer for the modified Carbamates chromatogram: we reversed the two reagents. The OPA reagent was pumped in the Reagent One position, and the Hydrolysis reagent was pumped in the Reagent Two position. Thus 1-Naphthol, which is naturally fluorescent, appears full-sized. The other Carbamate peaks have different sizes due to their varying rate of hydrolysis – the high pH of the OPA reagent will allow for some but not complete hydrolysis prior to detection.

Chromatography Quiz: Amino Acid Analysis

Identify the error made when running the Amino Acids chromatogram below and win a prize! Simply email your answer and your full contact information to Rebecca at rlsmith@pickeringlabs.com by March 1st in order to win. The troubleshooting answer and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission).

Amino Acid Analysis of Physiological Fluids:

Pickering Standard: 011006P Native Sample Standard 0.25 µmole/mL, 10 µL injection

Pickering Column: 0354100T High Efficiency Lithium Cation-exchange Column, 4.0 x 100 mm

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

Column Temperature: 36 °C

Flow rate: 0.35 mL/min

Eluent Gradient:
Amino Acid Analysis of Physiological Fluids

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, 570nm for primary amino acids, 440nm for secondary amino acids UV-Vis Detector
Hint: Assume in this case that both Guard and Analytical column are good. For more information, search standard Amino Acid chromatogram.