Restek at EPRW 2024

16-20 September 2024, Zürich, Switzerland

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VENDOR SEMINAR:

Is an Inert LC-Column Hardware Beneficial for Pesticide Analysis? Innovative Liquid Chromatography Techniques and Columns

Diego Lopez (presenter), Tina Brandscher, Hansjörg Majer
Restek Corporation

Abstract
In pesticide analysis as well as in plant toxin analysis, screening methodologies are often used. In these multi-compound analyses, the peak form is crucial to identify and quantify your analytes of interest.
Those multi-compound screenings include a variety of chemical classes with different and sometimes difficult behavior. For example, a lot of metal-sensitive compounds tend to interact with active spots of the metal surface in the analytical pathway of an LC-Instrument or are even forming chelates with these surfaces. The majority of these active surfaces are in the column and not in the instrument itself, especially in the frits at the beginning and end of the column.
In this presentation, we are showing the benefits of a CVD passivation technique to minimize these interactions from the beginning, making priming of the analytical system with either matrix of expensive reference standards obsolete.
In addition, we will discuss the use of dual-bed SPE cartridges as enrichment and clean-up tool in the analysis of organochlorine-pesticides and how these suppress matrix-effects and enhance Limits of Quantification.

POSTER PRESENTATIONS:

GC-MS/MS 200+ Multiresidue Pesticide Screening Workflow-Comparison of a Conventional 30 m Column and an LPGC Kit

Thursday, September 18, 5:00-6:00 p.m.
Friday, September 19, 5:00-6:00 p.m.

Tina Brandscher (presenter), Jana Hepner, Joseph Konschnik, Chris English
Restek Corporation

Abstract
Throughput is one of the most important parameters in the lab. While there are numerous ways to increase the speed of analysis, the low-pressure gas chromatography (LPGC) is unique in going towards short, wider bore column rather than short and narrower one. Coupling this type of column with a narrow guard column with a restrictor allows a normal head pressure at the inlet, while the analytical column is operated under near-vacuum conditions. The low pressure inside the wide-bore column shifts the optimum linear velocity about a factor 7 higher, which allows for faster analysis without a total loss of efficiency. The wider ID and thicker film provide also higher capacity, robustness and inertness. To demonstrate the technique, spinach was spiked with over 200 pesticides at two levels, 100 ppb and 10 ppb and analysis on conventional column (Rxi-5MS column, 30 m x 0.25 mm x 0.25 μm) was compared to the analysis on the LPGC column set.

A Hybrid Stationary Phase of Ion-Exchange and Hydrophilic Interaction Chromatography for the LC/MS of Polar Compounds

Wednesday, September 17, 5:00-6:00 p.m.
Friday, September 19, 5:00-6:00 p.m.

Diego A. Lopez, (presenter), Shun-Hsin Liang
Restek Corporation

Abstract
A hybrid ion exchange/HILIC column has been developed for the LC/MS analysis of polar compounds. The phase offers the possibilities of separation of ionic and polar compounds through ion exchange, HILIC or the combinations of both mechanisms, under typical LC/MS mobile phase conditions. Unlike a typical HILIC column, the column reaches equilibrium quickly and reproducibly. The applicability and versatility of the column have been demonstrated by the LC/MS analyses of a wide range of polar analytes. These include the determination of glyphosate and 16 other polar contaminants in food and water matrices, accurate quantification of a large panel of 45 underivatized amino acids in human plasma, and detection of ultrashort chain and conventional per- and polyfluoroalkyl substances (PFAS) in water.

Highly Efficient LC-MS/MS Analysis of Organophosphorus Pesticides Utilizing ARC-18 Column Selectivity with Inert Column Technology

Thursday, September 18, 5:00-6:00 p.m.
Friday, September 19, 5:00-6:00 p.m.

Tina Brandscher (presenter), Hansjörg Majer, Paul Conolly, Diego Lopez
Restek Corporation

Abstract
Organophosphorus pesticides (OPPs) play a pivotal role in modern agriculture, aiding in pest control and enhancing crop yield. OPPs are inexpensive and efficient and account for a significant portion of pesticides used globally. Despite their benefits, these pesticides are toxic, and their extensive use raises concerns regarding environmental contamination and human health risks. Therefore, careful analysis and monitoring is necessary.
However, the analysis faces sensitivity and recovery issues due to their reactivity with metal surfaces in conventional columns, resulting in tailing peaks and low sensitivity. In this work, Restek look to establish the benefits of coated column technologies by comparing methods developed on Inert and Standard Stainless-Steel hardware. The coating combined with our selective stationary phases resulted in exceptional analyte recoveries, lower detection limits and better peak shape. The signal heights and areas compared to conventional columns were doubled. In addition, time-consuming conditioning and complicated passivation belong to the past.