Study of alkyl phosphates in industrial petroleum mixtures by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry

Abstract

Dialkyl phosphate esters used as gellants in some oil well fracturing processes for conventional oil production can result in contamination of the collected crude. Though the exact mechanism is unclear, such compounds form volatile phosphorus that compromises refinery processes. Our initial research involved producing a comprehensive two-dimensional gas chromatographic method (GC × GC) for the detection and quantification of alkyl phosphate esters in petroleum samples, which surpassed the current method employed in sensitivity and speciation capabilities. However, selective detection is required for such analytes in petroleum matrices. This article describes the application of GC × GC with time-of-flight mass spectrometry for selective detection to the analysis of di- and tri-alkyl phosphates in petroleum samples. Features in the electron impact mass spectra of alkyl phosphates are discussed along with the GC × GC retention characteristics of the compounds. Based on these discussions, a preliminary classification and quantification of alkyl phosphate contamination in a suite of industrial samples is then presented.

Qualitative and quantitative approaches in comprehensive two-dimensional gas chromatography

“…The background near the peak can also be subtracted from the peak volume using this method. In addition to integration of the 3D chromatogram, summation of peak areas (or heights) of the modulated peaks has been reported and is typically used in most commercial quantitation software packages [24,33,38,39,[47][48][49][50][51]. Hyoetylaeinen et al compared quantitative results by both methods (peak volume and summation of the areas of the modulated peaks) and determined that they were in agreement [43].…”

Profiling Alkyl Phosphates in Industrial Petroleum Samples by Comprehensive Two-Dimensional Gas Chromatography with Nitrogen Phosphorus Detection (GC × GC–NPD), Post-column Deans Switching, and Concurrent Backflushing

“…We have previously demonstrated the use of GC × GC with selective detection to quantify alkyl phosphates in petroleum samples. A TOFMS detector may be used directly for the measurement of alkyl phosphates, although it is expensive and not the best choice for routine monitoring in a refinery environment. For this situation, a NPD is a better choice, although it requires a Deans switch for detector selection to divert excess silylation reagents at the start of a chromatogram to a FID .…”

Unique ion filter—A data reduction tool for chemometric analysis of raw comprehensive two‐dimensional gas chromatography‐mass spectrometry data

“…When coupled with a mass spectrometer, the separation potential of GC × GC is further enhanced by the rich data generated from the detector. GC × GC‐MS has been widely applied in various areas of analysis such as petroleum [5–14], environmental [15–22], metabolomics [23–29], etc. Recent reviews have highlighted several areas where GC × GC‐MS has been applied [30–35].…”