Special Issues-05-02-2017

Drinking water is an important part of environmental exposure, especially for small children. Countries around the world have put regulations in place to monitor drinking water quality for a wide range of hazardous compounds.

With computational chemistry, chemists can now study chemical phenomena by performing computationally intense calculations on computers rather than examining reactions and compounds experimentally. This is especially attractive when the laboratory experiments are time consuming, costly, dangerous, or difficult. Modern computational chemistry tools are capable of determining molecular structures, molecular spectra, and energetics, and of elucidating reaction pathways and chemical reaction products.

The analysis of oil samples containing many thousands of constituents best illustrates the benefits of ion mobility MS for complex samples. Here, we test the limits of ion mobility MS to discern differences between batches of Copaxone, a highly complex drug containing billions of peptides, and various purported generic versions of the drug.

Simultaneous, enantiomer-specific identification of chiral molecules in multicomponent mixtures is extremely challenging. With mass-selected photoelectron circular dichroism (MS-PECD) using an electron–ion coincidence imaging spectrometer, a compound can be identified as chiral without the need for any prior enantiomeric separation or enantiomer-selective complexation.

High resolution mass spectrometry with nano-LC is used for protein identification and quantification in both top-down and bottom-up proteome analysis. Reliable instrumentation in combination with ultrapure mobile phases is essential for data integrity. Premixed 80% acetonitrile with 0.1% formic acid (LS122-500) and water with 0.1% formic acid (LS118-500) were designed to produce a consistent chromatographic performance using this instrument system. In this study, these mobile phases were used extensively to evaluate several factors which can affect separation of protein digests such as peak retention, peak repeatability, and sample carryover. Our results demonstrated excellent chromatographic performance using Thermo Scientific EASY-nLC 1200 LC system and Thermo Scientific LTQLX ™ ion trap mass spectrometer with the specialized premixed mobile phases.

In this study, a simple method was used for extraction and concentration of trace organic compounds in water, followed by injection using a coiled wire filament and GC–MS analysis. Common semivolatile organic compound contaminants at low parts-per-billion levels were detected in less than 10 min.

By switching to a Raptor C18 column, labs can process more samples per hour while still meeting fluorochemical method requirements.

Determination of PBDE congeners can be performed at high sensitivity with good accuracy using the GCMS-TQ8050.

Click the title above to open the May 2017 issue of Current Trends in Mass Spectrometry, Volume 15, Number 2, in an interactive PDF format.