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MB Sample ID: SA255610

Local Sample ID:h3
Subject ID:SU002643
Subject Type:Cultured cells
Subject Species:Homo sapiens
Taxonomy ID:9606
Cell Strain Details:MDA-MB-231

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Combined analysis:

Analysis ID AN004190
Analysis type MS
Chromatography type GC
Chromatography system HP GCD 1800B
Column Agilent PoraBOND Q (25m x 0.32mm x 0.5um)
MS Type EI
MS instrument type Single quadrupole
MS instrument name Agilent/HP 5972 MSD
Units pg/hr/ug and g/hr for media


MS ID:MS003937
Analysis ID:AN004190
Instrument Name:Agilent/HP 5972 MSD
Instrument Type:Single quadrupole
MS Type:EI
MS Comments:Calibration was performed using standard gases (BOC Specialty Gases, Woking, UK). Linear regression of calibration curves confirmed strong, positive linear relationships between observed compound peak areas and moles of gas injected for each VOC (r2 > 0.9 in all cases). For compounds not purchased in gaseous state (BOC Specialty gases, as above), 1–2 mL of compound in liquid phase was injected neat into butyl sealed Wheaton-style glass vials (100 mL) and allowed to equilibrate for 1 h. 1 mL of headspace air was then removed from neat vial headspace using a gas tight syringe (Trajan, SGE) and injected into the headspace of a second 100 mL butyl sealed Wheaton-style glass vial. This was then repeated, and 1 mL of the 2nd serial dilution vial was injected into the GCMS system with 29 mL of lab air to give ppb concentrations. This was performed for methanethiol (MeSH (SPEXorganics, St Neots, UK)), isoprene (Alfa Aesar, Ward Hill, MA, USA), acetone (Sigma-Aldrich, Burlington, MA, USA), 2- & 3-methyl pentane and n-hexane (Thermo Scientific, Waltham, MA, USA). Reported compounds detected by the GC/-MS were confirmed by matching retention times and mass–charge (m/z) ratios with known standards. Equation 1: [VOC](ppt)=(CF x 〖10〗^12 x Peak area x Calibration slope)/n Equation 1 outlines the approach to calculating VOC concentrations in parts-per-trillion-by-volume, or pptv. Here Peak area refers to the combined peak areas for the mass-charge ratios identified in Table 1. Multiplying Peak areas by their associated calibration curves (Calibration Slope) generate molar amounts which, when divided by the number of moles of headspace air injected (n), generate a unitless (moles compound/moles of air) ratio. Pptv concentrations are then obtained by multiplying this unitless ratio by 1x1012. For clarity, part-per-billion-by-volume values would be obtained by multiplying the unitless ratios by 1x109, or one billion. Sample VOC concentrations were then normalised to CFC-11 concentrations (240 parts-per-trillion-by-volume (pptv)) through multiplication by a “correction factor”, or CF, Equation 1). CFC-11 was used as an internal standard, since atmospheric concentrations of CFC-11 are globally consistent and stable (Redeker et al., 2007). Quantification of Styrene was done as above but normalisation to CFC-11 was not possible under flushed, hypoxic conditions. NEGATIVE VALUES IN DATA SHOW CONSUMPTION OVER TIME. VARIATION IN SCALE BETWEEN MEDIA SAMPLES ARE DUE TO NORMALISATION OF CELLULAR DATA TO PROTEIN. AS DESCRIBED, MEDIA VALUES ARE SUBTRACTED FROM CELLULAR DATA PRIOR TO NORMALISATION AND EXPRESSED AS PG/HR/UG.