Abstract:

This dataset reports data from a method using proton-transfer-reaction mass spectrometry (PTR-MS) to detect n-alkanes. The method involved modifying the ion source and drift tube conditions to change the relative amount of primary ions (hydronium (H3O+), dioxygenyl (O2+), nitrosonium (NO+)) in the drift tube. Data includes signal intensity (counts per units second) for four n-alkanes at 1 water flow rate, 3 sensitivities, 5 electrical fields, and 5 source-out voltages. Additionally the sensitivity of 9 straight chain alkanes detected by proton transfer, charge transfer, and hydride abstraction are reported. The PTR-MS method was validated by analyzing gas phase n-alkanes evaporated from a sample of MC252 oil. The evaporated n-alkanes were measured after 2, 8, and 12 hours. PTR-MS data were compared to the amount of n-alkanes in the liquid phase of fresh oil and after 2, 8, and 12 hours as measured by GCxGC. The concentration of n-alkanes measured in the liquid phase and gas phase are reported. This dataset supports the paper Amador-Munoz, O. , Misztal, P.K., Weber, R., Worton, D.R., Zhang, H., Drozd, G., Goldstein, A.H. (2016). Sensitive detection of n-alkanes using a mixed ionization mode proton-transfer-reaction mass spectrometer. Atmospheric Measurement Techniques, 9, 11, 5315-5329. doi:10.5194/amt-9-5315-2016.

Suggested Citation:

Amador, Omar. 2017. Dataset for: Sensitive detection of n-alkanes using a mixed ionization mode proton-transfer-reaction mass spectrometer. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7251GM0

Publications:

Amador-Muñoz, O., Misztal, P. K., Weber, R., Worton, D. R., Zhang, H., Drozd, G., & Goldstein, A. H. (2016). Sensitive detection of <i>n</i>-alkanes using a mixed ionization mode proton-transfer-reaction mass spectrometer. Atmospheric Measurement Techniques, 9(11), 5315–5329. doi:10.5194/amt-9-5315-2016

Purpose:

The purpose of the study was to show how to optimize proton-transfer-reaction mass spectrometry to measure n-alkanes and other volatile organic compounds while making reagent ions available.

Data Parameters and Units:

Worksheet - Tables: n-alkane = name of n-alkane (n-Decane, n-Undecane, n-Dodecane, n-Tridecane), amount of n-alkane in evaporated (gas-phase) oil determined by proton-transfer-reaction mass spectrometry (PTR-MS) (milligrams/100 milliliters) and the remaining liquid phase measured by gas chromatography x gas chromatography (GCxGC) at 3 times points (2 hours, 8 hours, 12 hours) and in fresh oil as determined by GCxGC. Worksheet – Fig2a: signal intensity (cps = counts per unit second) at for 4 different mass to charge (m/z) ratios (m/z 19, m/z 30, m/z 32, m/z 37), and 3 sensitivities (cps/parts per billion volume (ppbv) m/z 85, m/z 86, m/z 87) for n-hexane at low water flow (sscm = standard cubic centimeters per second), and 5 reduced electrical fields (E/N) (Td = Townsend (83, 91, 101, 109, 122)), and 5 source out voltages (USO) (V= volts (60, 90, 120, 150, 180). Worksheet –Fig2b: signal intensity (cps) at for 4 m/z ratios (m/z 19, m/z 30, m/z 32, m/z 37), and 3 sensitivities (cps/ppbv) m/z 141, m/z 142, m/z 143) for n-decane at low water flow (sscm), and 5 E/N (Td (83, 91, 101, 109, 122)), and 5 USO (V (60, 90, 120, 150, 180). Worksheet – FigS1a: signal intensity (cps) at for 4 m/z ratios (m/z 19, m/z 30, m/z 32, m/z 37), and 3 sensitivities (cps/ppbv) m/z 127, m/z 128, m/z 129) for n-nonane at low water flow (sscm), and 5 E/N (Td (83, 91, 101, 109, 122)), and 5 USO (V (60, 90, 120, 150, 180). Worksheet – FigS1b: signal intensity (cps) at for 4 m/z ratios (m/z 19, m/z 30, m/z 32, m/z 37), and 3 sensitivities (cps/ppbv) m/z 155, m/z 156, m/z 157) for n-undecane at low water flow (sscm), and 5 E/N (Td (83, 91, 101, 109, 122)), and 5 USO (V (60, 90, 120, 150, 180). Worksheet – FigS1c: signal intensity (cps) at for 4 m/z ratios (m/z 19, m/z 30, m/z 32, m/z 37), and 3 sensitivities (cps/ppbv) m/z 169, m/z 170, m/z 171) for n-dodecane at low water flow (sscm), and 5 E/N (Td (83, 91, 101, 109, 122)), and 5 USO (V (60, 90, 120, 150, 180). Worksheet- Fig3a: signal intensity (cps) at m/z 32 of m/z 142 (cps/ppbv) at 5 E/N (Td (83, 91, 101, 109, 122)), and 5 USO (V (60, 90, 120, 150, 180)) for n-decane Worksheet- Fig3b: signal intensity (cps) at m/z 30 of m/z 141 (cps/ppbv) at 5 E/N (Td (83, 91, 101, 109, 122)), and 5 USO (V (60, 90, 120, 150, 180)) for n-decane Worksheet – Fig4a: signal intensity (cps) at m/z 19 of m/z 161 (cps/ppbv) at 5 E/N (Td (83, 91, 101, 109, 122)), and 5 USO (V (60, 90, 120, 150, 180)) for n-decane-water cluster (M*H3O+) Worksheet – Fig4b: sensitivity (cps/ppbv) of n-decane at m/z 143 and n-decane-water cluster at m/z 161 at 5 E/N (Td (83, 91, 101, 109, 122)), and 5 USO (V (60, 90, 120, 150, 180)) Worksheet – Fig5a: sensitivity normalized to H3O+ (ncps = normalized counts per second)/ppbv) of 9 n-alkanes at 83 Td, USO = 180 V and H3O+ = 1 sscm detected by proton transfer Worksheet – Fig5b: sensitivity weighted to sum (NO+ + O2+) (cps/ppbv) of 9 n-alkanes at 83 Td, USO = 180 V and H3O+ = 1 sscm detected by charge transfer Worksheet – Fig5C: sensitivity weighted to sum (NO+ + O2+) (cps/ppbv) of 9 n-alkanes at 83 Td, USO = 180 V and H3O+ = 1 sscm detected by hydride abstraction Worksheet – Fig6: ionization energy (IE, eV= electronvolt) of n-alkanes, weighted sensitivities to O2+, detected by charge transfer

Instruments:

Proton-transfer-reaction mass spectrometry (PTR-MS) gas chromatography x gas chromatography (GCxGC)

Individual Files: