| Sample Introduction | Extraction solvent's properties cause sub-optimal separations (peak splitting, band broadening, retention time shifting) | Potentially a broad range of compounds could be affected. | Optimize the analytical methodology to reduce issues.
Verify the responses of compounds that may be affected in other Orthogonal Analytical Methods (e.g. Direct Injection GC/MS for hexane) |
| Chromatography | Some compounds with specific functional groups will show sub-optimal chromatography or will not elute/remain adsorbed on the chromatography column | Acidic compounds (pKa below the mobile phase pH), polar, ionic, or zwitterionic compounds), large polymeric additives (e.g., Tinuvin 622) | Optimize the analytical methodology to reduce issues.
Verify the responses of compounds that may be affected in other Orthogonal Analytical Methods |
| Chromatography | Compounds eluting as broad humps or repetitive series (Siloxanes, Polyols, Surfactants) may mask co-eluting compounds by ion suppression | Compounds, co-eluting with the repetitive series of oligomers. | Screen chromatogram with an internal database could discover and identify these compounds (after deconvolutiona). Verify the response of those compounds in other analytical screening methods (e.g., LC/MS APCI/ESI direct injection; derivatization GC/MS) |
| Mass spectrometry: ESI and APCI | Compounds “react” with mobile phase and original compound is omitted (e.g. in-source adduct formation in ESI or in-source methoxylation during APCI) | Silanes | Experience with the method will reveal those compounds are subject to these artifacts.
Consider orthogonal analytical method (chromatography and/or ionization technique) that does not degrade analyte. |
| Mass spectrometry: APCI and ESI | Compounds are poorly or not ionized by the ionization technique | Perfluorinated organic compounds in APCI (e.g. PFAS), polycyclic aromatic hydrocarbons, esters | Verify compounds with other Ionization Mode (e.g., ESI for perfluorinated compounds).
Consider an orthogonal detection technique e.g. UV/DAD to detect compounds with chromophoric groups. |
| Mass spectrometry: APCI and ESI | Compounds with low Mw, very high MW, or multiple charges may be missed because they fall outside the scanned mass range | Formaldehyde, acrylic acid, small amines, small thiols, dicarboxylic acids, etc. … | Acids: consider aqueous extracts analysis via IC.
Formaldehyde: consider either GC/FID or specific method (e.g. LC/UV after derivatization).
Small amines and thiols: consider specific method. |
| Mass spectrometry: APCI | Thermolabile compounds may be degraded in the ion source | Thermolabile Compounds | Experience with the method will reveal those compounds that can degrade and what artifact(s) is formed.
Consider another ionization technique (e.g. ESI). |