Poster presented by Adam Dicapro at the 3rd Carolina NMR Symposium, Kannapolis, NC, November 6, 2014
Process NMR Associates has developed an extension of its 1H NMR analysis of Aloe Vera raw materials and products analysis. Powder aloe vera raw materials (100x/200x) can be analyzed directly and juice samples (1x, 5x, 10x, commercial products) must be freeze dried for this analysis. The whole leaf markers utilized in this test to indicate the presence of whole leaf material are iso-citrate and iso-citrate lactone which are formed in the green leaf part of the aloe plant as part of the citric acid cycle. It is possible to assign and quantify the following components of an aloe vera juice or powder:
* aloe vera components: acemannan, glucose, malic acid
* whole leaf markers: isocitrate, iso-citrate lactone, citric acid
* degradation products: lactic acid, acetic acid, fumaric acid, pyruvic acid, formic acid, succinic acid, and ethanol
* adulterants: maltodextrin
* preservatives: sorbate, benzoate
* additives: sucrose, fructose, glycine, flavorants (contain ethanol and propylene glycol)
For the components above it is possible to obtain a wt% of that component in a juice sample – the freeze drying process is then used to determine the wt% solids in the juice and the dry weight concentrations of the organic components in the solids.
Currently testing of aloe vera raw materials revolve around acemannan and whole leaf marker content and the presence of glucose. Process NMR Associates method can perform this analysis but also tell you the “quality” of the aloe vera raw material – the absolute concentrations of degradation products can tell you a lot about the exposure of the raw material to:
* excessive heat (hydrolyzation of acemannan acetyl groups to acetic acid (vinegar) or formic acid)
* lactobacillus bacteria (found on the skin of the aloe vera plant – these bacteria “eat” malic acid and produce lactic acid)
* enzymatic processes (enzymes found in the aloe vera plant itself can cause degradation to succinic acid or fumaric acid
The figure below shows the NMR assignment of a whole leaf juice that has been freeze dried. From the molar ratios of the various 1H NMR peaks it is possible to obtain a wt% value for all components by comparison with a nicotinamide internal standard (spectral range not shown) and the molecular weight of the component molecule or monomer unit.
1H NMR spectroscopy observes signals from all protons in the sample simultaneously. Aloe vera components, preservatives, and degradation products yield peaks at specific chemical shifts which can be integrated and quantified. Observations are made on the following peaks:
Nicotinamide – Internal NMR Standard: 1) 8.85 ppm, 2) 8.2 ppm (often coincides with formic acid), 3) 7.55 ppm, 4) 8.65 ppm
Glucose – C1 proton for alpha conformation at 5.2 ppm (doublet) and C1 proton for beta conformation at 4.6 ppm (doublet)
Malic Acid – CH at 4.35 ppm (multiplet), CH2 at 2.4-2.8 ppm (multiplet)
Acemannan – CH3 resonances of acemannan acetylation – fingerprint distribution of methyl resonances from 2.0-2.2 ppm
Lactic Acid – CH3 Peak at 1.33 ppm (doublet)
Acetic Acid – CH3 peak at 1.92 ppm (singlet)
Succinic Acid – 2 x CH2 peak at 2.5 ppm (singlet)
Formic Acid – Aldehyde Resonance at 8.2 ppm (singlet)
Ethanol – CH3 peak at 1.18 ppm (triplet)
Pyruvic Acid – CH3 peak at 2.35 ppm (singlet)
Citric Acid – 2 x CH2 resonances at 2.4 to 3.0 ppm (multiplet)
Iso-Citrate (Whole Leaf Marker) – CH at 4.25 ppm (doublet)
Iso-Citrate Lactone (Whole Leaf Marker) – CH at 5.05 ppm (doublet)
Benzoate – ortho-protons (2H) give peaks at 7.8 ppm.
Sorbate – CH3 peak is observed at 1.77 ppm (doublet) olefin protons observed at 5.7, 6.15, &7 ppm.
Fumaric Acid – CH peak at 6.55 ppm (singlet)
Sucrose – C1 proton observed at 5.4 ppm (doublet)
Maltodextrin – qNMR protons observed at 5.4 ppm
Maltodextrin is readily observed and quantified by 1H NMR – in the figure below is an example of a 100x and a 200x aloe vera gel powder – the 100x sample contains 50 wt% maltodextrin – the peaks at 5.4 and in the 3.5-4.0 ppm region are used to quantify the presence of maltodextrin.
Process NMR Associates is currently the only company providing a detailed breakdown of the components of aloe vera including quantitation of the whole leaf markers. Dry weight limits of acemannan, whole leaf markers, and maltodextrin are required for aloe vera raw material certification and quality control.
In the food industry it is found that most fruits, beverages, and dairy products contain a complex mixture of these same organic acid chemistry components. 1H NMR has a unique advantage in the analysis of these types of materials as NMR requires very little sample preparation and the data can be used to unequivocally identify the presence of single component chemistries and to quantify their presence in a single 15-30 minute analysis. Process NMR Associates are available to develop NMR based methodologies on any of these types of food systems and would welcome discussion of this with potential customers. Customers are not charged for initial consultation and project scoping. These NMR methods are universally applicable on NMR systems from 200-900 MHz. If you are interested please contact John Edwards (Tel: +1 (203) 744-5905)
Talk 1 by John Edwards
Mutivariate Analysis of 1H and 13C NMR Data of Residual Catalytic Cracker Feed-Streams: NMR Pre-Processing Strategies that Allow the Development of Predictive Models of Physical and Chemical Properties that are Independent of NMR Instrument Magnetic Field Strength
John C. Edwards*# and Jincheol Kim†
*Process NMR Associates, LLC, 87A Sand Pit Rd, Danbury, CT 06810 USA
† SK Innovation Co., Ltd, SK Innovation Technology Center, 140-1, Wonchon-dong, Yuseong-gu, Daejeon 305-712, Korea
Historically refinery control engineers are familiar with GC derived chemical properties such as aromatics, benzene, PONA, olefins in wt% or vol%, as well as physical properties such as distillation, viscosity, conradson carbon, sulfur, density, etc. We have developed generally applicable multivariate regression methods that allow many of these familiar chemical and physical properties to be derived from quantitative 1H or 13C NMR data. We have also developed magnetic field independent data manipulation methods that allow 1H or 13C NMR derived parameters to be utilized as the X matrix “spectral” data rather than the spectra themselves. This allows field independent models to be developed as these parameters are calculated from the spectrum and are the same regardless of the magnetic field strength at which the NMR data was collected. This has implications with respect to calibration transfer between laboratories and analyzers. In this work we describe the application of these methods to feed-streams to a residual catalytic cracker (RCC), which represents the core gasoline and diesel production facility in many refineries.
Talk 2 by Paul Giammatteo
Practical Applications of Compact High-Resolution 60 MHz Permanent Magnet NMR Systems for Reaction Monitoring and Online Process Control
John Edwards*, Paul Giammatteo*#, Mark Zell†, and David Foley†
* Process NMR Associates, 87A Sand Pit Rd, Danbury, CT, 06810 USA
† Pfizer Global Research and Development, Groton Laboratories, Eastern Point Road, Groton, CT 06340 USA
Process NMR Associates will be exhibiting the Spin Pulse range of TD-NMR spectrometers as well as the Aspect Italia 60 MHz high resolution NMR system – See us at the Cosa-Xentaur booth in the exhibition.
For more details on IFPAC visit http://www.ifpac.com/
The presentations from the RSC symposium have been posted for download the RSC site at:
Short Course on Process NMR and MRI to be presented at the IFPAC Meeting (http://www.ifpac.com/)
When: Monday, January17, 1:00pm to 5:00pm, and continues on Tuesday January 18, 8:00AM to 12 noon
Location: Baltimore Marriott Waterfront
Instructors: Michael J. McCarthy, Professor of Engineering, University of California, Davis, CA
Paul J. Giammatteo, Ph.D., Process NMR Associates LLC, Danbury, CT
The course is specifically designed and organized for industry professionals who want to add to their knowledge-base on magnetic resonance and process analytical technology. Topics include compositional analysis, rheological characterization, measurement of the state of mixing, visualizing transport and product stability as well as recent advances in process magnetic resonance sensors. This course will bring you up-to-date on the latest information concerning the applications and state-of-the art instrumentation for process magnetic resonance.
* Introduction to Process NMR Magnetic resonance theory
– Time-domain, High resolution, Diffusion, Imaging
– Spectrometers, magnets, probes
* Coupling the sensor to the process
* Applications will include:
– Composition measurement
– Property measurement
– Rheology measurement
– Product structure
For Details contact Paul Giammatteo Tel: (203) 744-5905 or Michael McCarthy Tel: (530) 752 8921