Special Issues-07-01-2015

Experiments presented here demonstrate the suitability of LC–SAI-MS for the detection and quantification of pharmaceuticals, with limits of detection in the low parts-per-trillion range. A comparison of LC–ESI-MS to LC–SAI-MS also yielded favorable results for SAI.

We present a brief review of this year’s ASMS conference, which took place May 31–June 4, 2015, in St. Louis, Missouri.

A rapid, accurate, and reproducible method was developed for high-throughput testing of nicotine, cotinine, trans-3’-hydroxycotinine, nornicotine, norcotinine, and anabasine in urine. Data show that a fast and highly efficient analysis of these basic compounds can be achieved with the Raptor Biphenyl column using standard reversed-phase LC–MS mobile phases that are compatible with a variety of LC–MS instrumentation.

Compact mass spectrometry, in combination with suitable sample introduction techniques-such as the atmospheric solids analysis probe, thin-layer chromatography, and classical liquid chromatography techniques-can be used effectively for the detection and quantification of cannabinoids and pesticides in cannabis-related material and contraband.

Ionic contaminants in the water used in UHPLC analyses with MS detection method lead to adduct formation and reduced analytical signals because of ion suppression. In MS, the preferred ion type is the protonated molecular ion, especially in peptide analysis, since the partially mobile proton charge enables more meaningful fragmentation analysis, as compared to a sodiated peptide ion. Moreover, the occurrence of protonated analyte signals indicates that solvents and reagents, as well as the MS instrument used in analyses, are clean and do not contribute any contaminating cationic components to the analytical process. In the experiments presented here, it was observed that the signal intensities of the protonated species decreased as the sodium ion concentration in the water increased. This was accompanied by an increase in the intensity of sodiated adducts.

Disinfection by-products (DBP) are an ever-present nuisance in the efforts to purify drinking water, wastewater, and municipal waters from various sources. An emerging class of DBP compounds with health effects is nitrosamines which result from chloramination or chlorination if the water is nitrogen-rich. Five of these nitrosamines have been listed on the US EPA’s new Contaminant Candidate List (CCL-3). Of the nitrosamines, the most common and problematic is N-nitrosdimethylamine (NDMA). The maximum admissible levels set by the US EPA are 7 ng/L for NDMA and 2 ng/L for N-nitrosodiethylamine (NDEA).

To translate the enormous potential of MS into meaningful, actionable, and safe test results in the specific setting of a clinical laboratory is a very substantial challenge. It is essential to realize that reliability is not inherent to this technology but must be addressed carefully and questioned systematically.

Click the title above to open the July 2015 issue of Current Trends in Mass Spectrometry, Volume 13, Number 3, in an interactive PDF format.