Chemometrics Archives - NMR Testing Laboratory

PNA to Present 4 Topics at the 2015 ACS North East Regional Meeting

May 17, 2015 by process nmr Beer, Benchtop NMR, Chemometrics, Cider, Energy, Herbal Supplement, NMR, PAT, Petroleum, qNMR

John Edwards of Process NMR Associates will be presenting 4 papers at the 2015 ACS Northeast Regional Meeting that will be held in Ithaca, NY, June 10-13, 2015.

ABSTRACT ID: 2283171
ABSTRACT TITLE: 1H qNMR of Alcoholic Cider – Analysis of Small Molecule and Residual Sugar Chemistry (final paper number: 43)
SESSION: Food Chemistry
SESSION TIME: 5:00 PM – 9:00 PM
PRESENTATION FORMAT: Poster
DAY & TIME OF PRESENTATION: Wednesday, June, 10, 2015, 5:00 PM – 9:00 PM
ROOM & LOCATION: Emerson Suites – Campus Center

ABSTRACT ID: 2283063
ABSTRACT TITLE: Nutritional Supplement and Diesel Fuel Application Development for Benchtop NMR Systems Operating at 42, 60, and 80 MHz – Equivalency with Supercon NMR (final paper number: 336)
SESSION: Analytical Chemistry
SESSION TIME: 9:00 AM – 11:30 AM
PRESENTATION FORMAT: Oral
DAY & TIME OF PRESENTATION: Friday, June, 12, 2015 from 9:45 AM – 10:05 AM
ROOM & LOCATION: 222 – Williams Hall

ABSTRACT ID: 2283105
ABSTRACT TITLE: Survey of Low Field NMR Spectrometer Platforms for Successful Screening of Sexual Enhancement and Weight Loss Supplements for Adulteration with Drugs and Drug Analogs (final paper number: 386)
SESSION: Medicinal Chemistry
SESSION TIME: 1:00 PM – 3:20 PM
PRESENTATION FORMAT: Oral
DAY & TIME OF PRESENTATION: Friday, June, 12, 2015 from 2:20 PM – 2:40 PM
ROOM & LOCATION: 302 – Williams Hall

ABSTRACT ID: 2283153
ABSTRACT TITLE: From Mash to Bottle: Chemistry of the Beer Brewing Process and NMR-based Quality Control (final paper number: 284)
SESSION: Food Chemistry
SESSION TIME: 1:30 PM – 3:10 PM
PRESENTATION FORMAT: Oral
DAY & TIME OF PRESENTATION: Thursday, June, 11, 2015 from 1:35 PM – 1:55 PM
ROOM & LOCATION: 202 – Williams Hall

Residual Catalytic Cracker – Heavy Petroleum Feedstream Properties from 1H NMR at 43 MHz

February 27, 2015 by process nmr Benchtop NMR, Chemistry, Chemometrics, Energy, NMR, PAT, Petroleum, Process NMR, qNMR, Reaction Monitoring, TD-NMR Tagged: NMR, Petroleum, RCC

Back in October we presented a talk at Gulf Coast Conference that concerned the prediction of the chemical and physical properties of heavy petroleum feeds being converted to higher value product in a residual catalytic cracker (RCC). Over the years we have analyzed these materials by 300 and 60 MHz NMR and obtained good PLS-regression models that can adequately predict properties for real-time process control and optimization in a petroleum refinery. With the advent of a large number of new benchtop NMR systems we have been convincing ourselves that these types of analyses can be performed by systems such as the Magritek Spinsolve 43 MHz. We ran a series of samples that had been sitting around our lab for 15 years by dissolving them at about 50 volume% in a 50/50 CDCl3/CS2 solvent system. For each sample we had laboratory test data for a number of chemical and physical properties of interest to process engineers. We regressed the lab data variability against the variability in the Magritek 43MHz 1H NMR spectra and obtained cross-validated PLS models. The presentation material is given here at this link – Gulf Conference Presentation – 43 MHz RCC Feedstream Regression Models

Nutritional Supplement and Diesel Fuel Application Development for Benchtop NMR Systems Operating at 42, 60, and 80 MHz – Equivalency with Supercon NMR

February 26, 2015 by process nmr Benchtop NMR, Chemometrics, Energy, Herbal Supplement, NMR, PAT, qNMR

Benchtop high-resolution NMR systems are available at a number of field strengths and probe configurations. However beyond the obvious academic instruction market for these instruments very few applications have been demonstrated across all available platforms and thus proving the general applicability of benchtop NMR technology to industrial quality control. We will present two chemometric-based applications that have been developed at 4 different field strengths utilizing Varian Mercury 300 MHz, Magritek Spinsolve 42 MHz, Aspect AI 60 MHz, and Thermo Picospin 80 MHz NMR systems. Partial-least-squares (PLS) regression correlations were obtained on all 4 platforms relating to:
1) Omega-3 fatty acid composition of samples taken from various points in a nutritional supplement manufacturing process. Excellent correlations were obtained on all 4 NMR instruments proving that NMR technology is applicable to in-lab, at-line. or on-line analysis of fish oil derived omega-3 fatty acid supplements. The 40 second NMR analysis effectively replaces a 60+ minute GC analysis.
2) Physical and chemical property determination of diesel fuels where excellent correlations were obtained between 1H NMR variability and parameters such as density, aromatic content by GC, hydrogen content by 1H TD-NMR (ASTM D7171 method), and sulfur content. Many more physical and chemical properties can be correlated to the 1H NMR spectrum allowing a single 40 second NMR experiment to predict 10-15 parameters that each require dedicated analyzers.
Finally, we will present the concept and initial results from an independent server-based NMR application software that can be utilized in conjunction with the NMR software of the current benchtop NMR systems, or alternatively as a stand-alone application platform. This software would effectively make chemometric and direct measurement NMR application ubiquitous across all NMR platforms.

A link to this presentation in PDF form is given here: PLS-Regression – 300_80_60_43 MHz NMR of Fish Oil Supplements and Diesel Fuel

From Atoms to Flavour: The Chemistry of Beer

December 8, 2014 by process nmr Beer, Chemistry, Chemometrics, NMR, Process NMR, qNMR, Reaction Monitoring Tagged: Beer, Brewing, Fermentation, Hop Chemistry, Malt Chemistry, NMR

Adam DiCaprio (ex PNA) gave an excellent Science Cafe Talk under the auspices of the ACS North Carolina Section at the Busy Bee Cafe in downtown Raleigh on December 2, 2014. CHanging gears from his previous talks he centered the discussion on malt and hop chemistry as well as an start-to-finish NMR analysis of production runs of a bottled commercial tavern ale. If you are interested in having Adam give a detailed chemistry seminar on beer at your section meetings please contact him directly at adam@process-nmr.com.

A PDF version of his talk is available here …. ACS Science Cafe Talk – Dicaprio – Busy Bee Cafe – Raleigh NC – 12-2-14

Comparison of 1H NMR Spectra Obtained at 42, 60, 82, and 300 MHz – Fish Oil Omega-3 Ethyl Ester Supplement Example

November 16, 2014 by process nmr Benchtop NMR, Chemistry, Chemometrics, NMR, PAT, Process NMR, qNMR

Process NMR Associates is currently developing NMR applications based on direct measurement of chemometric modeling on NMR data obtained on numerous NMR platforms. Our intention is to develop solutions that can be executed on any NMR platform. With this in mind we are currently developing a fish oil analysis application that can provide the EPA and DHA omega-3 fatty acid content of fish oil supplements manufactured by an ethyl ester esterification process. We have obtained data at 42 MHz, 60 MHz, 82 MHz and 300 MHz. The chemometric modelling yielded PLS models for all 4 field strengths that yield effectively the same result – DHA can be measured to +/- ~1.1 wt% and EPA can be measured to +/- ~2.2 wt% by a 40 second 1H NMR measurement. THe correlation is derived from a regression of the 1H NMR variability with primary GC analysis values.

This analysis has been shown for the 300 and 60 MHz data in a previous post on this blog. The same analysis was also obtained, with similar results, on 42 and 82 MHz platforms proving that individual applications can be automated and provided at all relevant frequencies of NMR analysis whether on superconducting lab systems or permanent magnet benchtop systems.

At each field strength the relative lineshapes are pretty much the same (<1 Hz at half height). The field strength differences mean that the same spectrum is dispersed across frequency space proportionate to the magnetic field. Figure 1 below shows the frequency space spectra obtained at all 4 field strengths on the same sample.

Figure 2 shows the same spectra displayed on the usual normalized chemical shift scale (ppm). In these spectra the data is stretched in order to allow the chemical shift comparison of the data. IN effect the 42 MHz NMR is stretched by a factor of 7, the 60 MHz data by a factor of 5 and the 80.2 MHz data by a factor of 3.7. The effect of the relative size of J coupling compared to the frequency space occupied by 1 ppm is an interesting observation to see directly. In traditional NMR analysis the resolution of various peaks was always the driving force for increasing the magnetic field strength of NMR instruments. With todays powerful PC’s and advanced software information can be garnished readily from any of these spectra by way of global spectral deconvolution or multivariate statistics.It is no longer necessary to obtain baseline resolution in order to integrate a resonance and obtain quantitative information.

THough the data is more closely packed together in the low field spectra it can be acknowledged that the same information is present in all 4 spectra. Automation approaches can be developed that will allow accurate measurement of quality parameters, component quantification, or structural verification to be performed on data obtained from any of these NMR systems.

The development of readily deployable NMR benchtop systems at an affordable price point must surely lead to the development of NMR into a more widely utilized technique outside of the realms of scientific study and quality control that NMR has thus far been involved.

1H NMR at 42, 60, 82, and 300 MHz — Figure 1: Comparison of 1H NMR spectra obtained on an omega-3 fish oil supplement obtained at 42, 60, 82, and 300 MHz displayed in frequency space. These spectra show the native spectra dispersion obtained at the different magnetic field strengths of the NMR spectrometers

CHemical SHift Scale Normalization of 1H NMR spectra obtained on the same sample at 42.5, 60.3, 82.3, and 300 MHz — Chemical Shift Scale Normalization (ppm) of 1H NMR spectra obtained on the same sample at 42.5, 60.3, 82.3, and 300 MHz. In these spectra the absolute frequency of the spectrum is divided by the spectrometer frequency to obtain a normalized spectrum where the chemical shift in ppm of the various peaks in the spectrum are observed at the same position on the ppm NMR scale. In this normalized view the relative proportion of a ppm that the J couplings represent in the 1H multiplets can be plainly seen.