Vitamin D2 and D3 25-hydroxy metabolites are important diagnostic markers for vitamin D status, but these compounds cannot be distinguished from their epimeric forms on a C18 column. The Raptor FluoroPhenyl column provides ample chromatographic resolution for these isobaric epimers, which possess unequal bioactivities, so accurate results are generated and thus the proper diagnosis can be made.
(PDF - 0kB)
Protein and particulate removal that’s fast, painless, and effective. Restek’s line of Resprep sample preparation products has expanded to include new 96-well protein precipitation (PPT) plates. Prepare serum, plasma, and other biological samples using the name you trust for quality, cleanliness, and performance.
Featured Application: 231 pain management and drugs of abuse compounds in under 10 minutes
The use of pain management drugs is steadily increasing. As a result, hospital and reference labs are seeing an increase in patient samples that must be screened for a wide variety of pain management drugs to prevent drug abuse and to ensure patient safety and adherence to their medication regimen. Restek's "Big Pain" LC-MS/MS methodology features a 231-compound multiclass drug and metabolite screen that can be performed in under 10 minutes with just one column: The Raptor™ Biphenyl.
(PDF - 0kB)
Viva wide pore HPLC columns offer the largest surface area available in 250-350 Å pores, giving maximum retention and resolution of proteins, peptides, and other large biomolecules. Includes product information and chromatography for the PEGylation of oxytocin.
A Rapid and Sensitive LC-MS/MS Method for the Analysis of Three Forms of Thyroid Hormones Using Raptor™ Biphenyl LC Columns
The Raptor Biphenyl column is excellent for rapid and sensitive analysis of thyroid hormones. With the method described here, concentrations of thyroid hormones as low as 2 pg/mL (T3) or 5 pg/mL (T4 and rT3) can be determined with less than 3.5 minutes of total analysis time. The analytical method is thus applicable to the clinical analysis of free thyroid hormone at low pg/mL levels.
(PDF - 0kB)
Separating fat‐soluble vitamins and their metabolites by LC can be quite time consuming, taking up to 20 minutes or longer by some methods. However, the new Raptor ARC‐18 LC column can analyze these difficult compounds using reversed phase chromatography (RPC) in much less time, which helps increase sample throughput and overall lab productivity. This technical poster presents methodology that provides excellent quantitative results for metabolites 25‐hydroxyvitamin D2 and 25‐hydroxyvitamin D3 in analysis times of less than 2 minutes. Parent compounds vitamin D2 and vitamin D3 eluted in less than 4 minutes.
(PDF - 0kB)
Fully porous UHPLC and superficially porous HPLC columns increase efficiency and peak capacity and decrease analysis times, but don't directly impact selectivity or retention. The Biphenyl phase utilizes aromatic selectivity and hydrophobic retention to give greater retention and selectivity, therefore offering advantages on throughput, data quality, sensitivity, and resolution in bioanalytical work.
(PDF - 0kB)
Raptor LC columns combine the speed of superficially porous particles (i.e., SPP or “core-shell”) with the resolution of highly selective USLC technology. Featuring Restek's most popular LC stationary phase, the rugged Raptor Biphenyl is extremely useful for fast separations in bioanalytical testing applications like drug and metabolite analyses, especially those that require a mass spectrometer (MS).
Characterizing Cellular Fatty Acid Methyl Ester (FAME) Profiles to Identify Bacteria Using Gas Chromatography
Dr. Radomír Čabala, Head of the Toxicology Department at the General University Hospital in Prague, presents work on the potential utility of GC-TOFMS analysis of cellular fatty acid methyl esters (FAMEs) in identifying clinically relevant bacteria.
Labs can save days of downtime by using an Rxi®-5ms column in assays similar to this high-throughput test method for cholesterol and low-level sterol metabolites. Here, extremely reproducible results were obtained using an Rxi®-5ms column, which gave highly consistent separations — even after 10,000 injections. Consistent performance and long column lifetimes increase productivity by reducing downtime associated with column changes and revalidation.
Viva Wide Pore HPLC columns are ideal for the separation of large molecules, as target analytes can enter the larger pores and access more of the surface area. Here we demonstrate the added retentive power of these columns, using the PEGylation of oxytocin as an example. Separation of these large, closely related compounds demonstrates the suitability of Viva Wide Pore columns for monitoring PEGylation reactions, and other large molecule applications.
A Viva C18 wide pore HPLC column resolves a tryptic digest of bovine serum albumin primarily into 1-2 peptide peaks, versus peaks of 3 or more peptides typically provided by conventional C18 columns. This superior resolution helps ensure more reliable identification of peptides in complex mixtures.