Use of ion mobility mass spectrometry to enhance cumulative analytical specificity and separation to profile 6-C/8-C-glycosylflavone critical isomer pairs and known-unknowns in medicinal plants.

INTRODUCTION: Plant medicine/herbal extracts are typically complex, encompassing a wide range of flavonoid diversity and biological benefits. Combined with a lack of standards; species authentication profiling is a challenge. A non-targeted screening strategy using two-dimensional (2D) separation and specificity of ultra-high-performance liquid chromatography ion mobility collision-induced dissociation mass spectrometry (UHPLC-IM-CID-MS) has been investigated, to identify the 6-C and 8-C-glycosylflavone isomer orientin/isoorientin and vitexin/isovitexin pairs in Passiflora species. Utilising available standards and "known-unknowns" a reference CCS (collision cross-section) speciation finger print for Passiflora extracts could be generated to illustrate species profiling. MATERIAL AND METHODS: SPE was performed to extract flavonoids of interest from powdered and ground Passiflora leaf. Chromatographic separation was achieved via UHPLC and analysis performed using positive/negative ion electrospray coupled with linear T-wave IM-MS (calibrated to perform accurate mass and CCS measurements). RESULTS: Comparative phytochemical screening of Passiflora alata, P. edulis, P. incarnata and P. caerulea leaf extracts has generated CCS, CID IM product ion spectra, 2D separation with UHPLC-IM-MS, enabling the unequivocal identification of flavone C-glycosides in complex extracts. A phytochemical reference CCS library was generated comprised of "knowns" and "known-unknowns". Isomers have been differentiated using a CCS metric enabling novel CCS specific isomeric quantitation of co-eluting isomers. CONCLUSIONS: The screening approach illustrated has the potential to play an important role in the profiling of medicinal plants to determine phytochemical make-up and improve consumer safety through generation of highly specific speciation profiles.

Fiber introduction mass spectrometry: determination of pesticides in herbal infusions using a novel sol-gel PDMS/PVA fiber for solid-phase microextraction.

An application of the direct coupling of solid-phase microextraction (SPME) with mass spectrometry (MS), a technique known as fiber introduction mass spectrometry (FIMS), is described to determine organochlorine (OCP) and organophosphorus (OPP) pesticides in herbal infusions of Passiflora L. A new fiber coated with a composite of poly(dimethylsiloxane) and poly(vinyl alcohol) (PDMS/PVA) was used. Sensitive, selective, simple and simultaneous quantification of several OCP and OPP was achieved by monitoring diagnostic fragment ions of m/z 266 (chlorothalonil), m/z 195 (alpha-endosulfan), m/z 278 (fenthion), m/z 263 (methyl parathion) and m/z 173 (malathion). Simple headspace SPME extraction (25 min) and fast FIMS detection (less than 40 s) of OCP and OPP from a highly complex herbal matrix provided good linearity with correlation coefficients of 0.991-0.999 for concentrations ranging from 10 to 140 ng ml(-1) of each compound. Good accuracy (80 to 110%), precision (0.6-14.9%) and low limits of detection (0.3-3.9 ng ml(-1)) were also obtained. Even after 400 desorption cycles inside the ionization source of the mass spectrometer, no visible degradation of the novel PDMS/PVA fiber was detected, confirming its suitability for FIMS. Fast (ca 20 s) pesticide desorption occurs for the PDMS/PVA fiber owing to the small thickness of the film and its reduced water sorption.

Fiber introduction mass spectrometry: determination of pesticides in herbal infusions using a novel sol-gel PDMS/PVA fiber for solid-phase microextraction.

An application of the direct coupling of solid-phase microextraction (SPME) with mass spectrometry (MS), a technique known as fiber introduction mass spectrometry (FIMS), is described to determine organochlorine (OCP) and organophosphorus (OPP) pesticides in herbal infusions of Passiflora L. A new fiber coated with a composite of poly(dimethylsiloxane) and poly(vinyl alcohol) (PDMS/PVA) was used. Sensitive, selective, simple and simultaneous quantification of several OCP and OPP was achieved by monitoring diagnostic fragment ions of m/z 266 (chlorothalonil), m/z 195 (alpha-endosulfan), m/z 278 (fenthion), m/z 263 (methyl parathion) and m/z 173 (malathion). Simple headspace SPME extraction (25 min) and fast FIMS detection (less than 40 s) of OCP and OPP from a highly complex herbal matrix provided good linearity with correlation coefficients of 0.991-0.999 for concentrations ranging from 10 to 140 ng ml(-1) of each compound. Good accuracy (80 to 110%), precision (0.6-14.9%) and low limits of detection (0.3-3.9 ng ml(-1)) were also obtained. Even after 400 desorption cycles inside the ionization source of the mass spectrometer, no visible degradation of the novel PDMS/PVA fiber was detected, confirming its suitability for FIMS. Fast (ca 20 s) pesticide desorption occurs for the PDMS/PVA fiber owing to the small thickness of the film and its reduced water sorption.

Application of a novel sol-gel polydimethylsiloxane-poly(vinyl alcohol) solid-phase microextraction fiber for gas chromatographic determination of pesticide residues in herbal infusions.

A simple and environmentally friendly methodology for headspace solid-phase microextraction (HS-SPME) using a new fiber coated with polydimethylsiloxane-poly(vinyl alcohol) (PDMS/PVA) is reported for the trace determination of organochlorine (OCP) and organophosphorus (OPP) pesticides in herbal infusions of Passiflora L. by GC-ECD. The capacity of the PDMS/PVA coating for the pesticides was compared to that of commercial PDMS fibers, with advantageous results. The effects of parameters such as the sample ionic strength, dilution of the infusion, extraction temperature and time were investigated. The optimized conditions for the determination of OCP and OPP in Passiflora L. infusions were extraction time and temperature, respectively, of 38 min and 67.5 degrees C, with 5 min of sample/headspace equilibration time. The analytical curves for the range between 0.04 ng mL(-1) to 6 ng mL(-1) of each compound presented a good quality (correlation coefficients of 0.921 or better). The detection limits for the OCP and OPP in these matrices varied from 0.01 ng mL(-1) (beta-endosulfan) to 1.5 ng mL(-1) (malathion). The sensitivity of studied methodology was adequate, as well as its accuracy (78.7-91.5%) and precision (R.S.D. = 1.2-14.2%).