Tighten Control of Distillation Processes with the New MXT®-1HT Sim Dist Column

By Barry Burger, Petroleum Chemist and Jan Pijpelink, Petrochemical Market Development Manager

Content previously published in Petro Industry News

High temperature crude oil simulated distillation using ASTM methods D6352 and ASTM D7500 presents many challenges to refineries and contract laboratories for the determination of petroleum distillates in the boiling range of 174°C to 720°C. Both the column construction and the polydimethylsiloxane polymer must be robust enough to withstand the high method temperatures without significant degradation. In addition, columns must yield a C50/C52 resolution value between 2 and 4, exhibit acceptable peak symmetry, and reliably produce accurate boiling point data. Accurate determination of the boiling range distribution of medium and heavy fractions using GC simulated distillation provides critical information regarding the composition of crude oil and other products related to refinery processes. While fused silica columns can be used, they are not the best option anymore for high temperature simulated distillation applications. Metal MXT®-1HT Sim Dist columns are a much better alternative. These new columns are more stable at 430°C than fused silica columns and easily meet all method criteria, even under accelerated conditions.

Fast, Definitive LC/MS/MS Analysis of THC and THC Metabolites in Urine Using an Ultra II® Biphenyl Column

Fast, Definitive LC/MS/MS Analysis of THC and THC Metabolites in Urine Using an Ultra II® Biphenyl Column

By Amanda Rigdon a, Clinical/Forensic Innovations Chemist, Becky Wittrig a, Ph.D., Global HPLC Specialist, and Takeo Sakuma b, Ph.D., Principal Application Scientist

a Restek Corporation, 110 Benner Circle, Bellefonte, PA 16823
b AB SCIEX, 71 Four Valley Drive, Concord, Ontario, Canada L4K 4V8

Good retention and peak shape allow direct quantification of THC-COOH-glucuronide.
Faster sample throughput than GC/MS methods--short analysis time and no derivatization.
Indisputable identification using two or more MRM transitions.

Pesticides in Dietary Supplements: Advantages of QuEChERS vs. PAM 303

GC Accessories Tech Tip

Pesticides in Dietary Supplements:

Advantages of QuEChERS vs. PAM 303

By Julie Kowalski, Innovations Chemist, Michelle Misselwitz, Innovations Chemist, Jason Thomas, Innovations Chemist, Jack Cochran, Director of New Business and Technology

Simple, cost-effective QuEChERS approach saves time and uses 20x less solvent.
GMP-friendly—prepackaged extraction salts and snap-and-shoot standards reduce human error.
Cartridge SPE cleanup removes matrix interferences, assuring accurate pesticide determination.

Meet New Requirements for Melamine Analysis at 1µg/g in Infant Formula

Meet New Requirements for Melamine Analysis at 1µg/g in Infant Formula

By Julie Kowalski, Ph.D., Innovations Chemist, Michelle Misselwitz, Innovations Chemist, and Jack Cochran, Director of New Business and Technology

Easily meet FDA requirements with simple, highly reproducible GC/MS method for 1µg/g melamine in infant formula.

FDA GC/MS method successfully transferred to meet new lower MRL requirements.
Highly reproducible retention times on Rxi®-5Sil MS column are key to accurate compound identification.
Leak-proof integrated guard column reduces matrix contamination and extends analytical column lifetime.

Melamine is a nitrogen-rich industrial compound used in the manufacture of plastics, flame-resistant products, and cleaning agents. It is not a legal food additive; however, it has been added to food products in order to falsely represent the amount of protein present, as protein level is often determined using simple, nonspecific nitrogen content assays (Figure 1). Melamine is not considered toxic alone at low doses; however, illnesses and deaths have been traced to exposure to melamine in the presence of cyanuric acid.

Tighten Control of Distillation Processes with the New MXT®-1HT Sim Dist Column