Alterations in glycan structures can have great biological significance. Of particular interest are sialylated glycans due to their involvement in biological phenomena, such as cell-cell adhesion and cell-pathogen interaction. This note discusses a technique that is a fast, simple, and reliable workflow for profiling N-linked glycans. It combines the benefits of the Thermo Scientific MALDI LTQ Orbitrap mass spectrometer with the homogeneity of sample distribution provided by a DHB/DMA matrix. The high mass accuracy and mass resolution provided by the Thermo Scientific Orbitrap detector enables confident structural discrimination without the aid of tandem MS. The ability to profile both sialylated and asialylated glycans with a single ionization mode in MALDI experiments makes the workflow especially practical. This ability is useful in determining the degree of silaylation relative to overall glycan composition.

This application note describes the use of MALDI on a Thermo Scientific LTQ Orbitrap hybrid mass spectrometer, and a unique MALDI matrix, to improve analysis of N-linked sialylated glycans.

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Today’s budget-limited LC/MS customers are looking for ways to increase throughput and flexibility of their mass spectrometers without sacrificing data quality or reliability. Multiplexing is a proven technology that can produce these results. Though there are different approaches to multiplexing, not all are created equal. This webinar discusses the following:

Currently, GC/MS is the method of choice for quantifying drugs of abuse. In recent years, however, many forensic labs have been switching to LC-MS/MS methods, which do not require time-consuming derivatization or extensive sample cleanup necessary in GC/MS analyses. Yet, many of the LC-MS/MS methods described in the literature either assay a limited number of illicit drug classes or do not include their primary metabolites of these illicit drugs.

This application note describes a method to assay multiple drugs of abuse including opiates, stimulants, depressants, and the primary metabolites of these illicit drugs.

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Imaging Mass Spectrometry (IMS) using matrix-assisted laser desorption ionization (MALDI) is being investigated using a linear ion trap with the overall goal of analyzing the distribution of various targeted therapies within patients' tumors. The drug chosen for evaluation is erlotinib which targets the epidermal growth factor receptor (EGFR), a type I receptor tyrosine kinase (TK) involved in cellular differentiation and proliferation, by binding to the ATP pocket and inhibiting the autophosphorylation of the receptor. Erlotinib has demonstrated clinical activity in non-small cell lung cancer, head and neck cancer, and ovarian cancer in Phase II studies. The sensitivity and MS/MS capabilities of the Thermo Scientific LTQ XL are exploited for the unambiguous determination of the distribution of this drug within human pancreatic tumors.

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A dual-cell linear ion trap (LIT) quadrupole mass spectrometer has been developed with enhanced performance over single-cell LITs in terms of improved scanning rate, resolution, MS/MS efficiency, and trapping efficiency. In commercially available LITs, the X-rods are displaced from the nominal quadrupolar r₀ in order to compensate for field distortions created by slots cut into the X-rods for ion ejection. The Y-rods do not include these slots nor the corresponding rod displacement, therefore resulting in a two-fold symmetric stretch (2FSS). In contrast, the dual-cell configuration incorporates four identical electrodes, where the r₀ is the same for both X and Y rods, resulting in a four-fold symmetric stretch (4FSS). This work investigates some fundamental differences between these LIT geometries.