Paul Giammatteo recently presented two papers at the Gulf Coast conference that was held in Galveston, Texas on January 20-21.

His first paper was entitled “Counting Carbons for Tighter Control: Combining GC and NMR to Improve Distillate Manufacturing” and centers on the topics of Simulated distillation correlated to 1H NMR.

The second paper was entitled “Analytical Data For Engineering Support: Improving the Lab/Process Interface”. This paper details the development of a series of heavy petroleum applications on a Smiths Detection FTIR-ATR spectrometer.

PDFs of the presentations can be obtained from the following links: 1) NMR Talk 2) FTIR-ATR Talk

Over the past few years balsamic vinegars have been the subject of a number or NMR studies to determine authenticity, degree of aduleration, and age. 1H NMR has been used to quantify the relative concentrations of a series of organic components (ethanol, fructose, glucose, acetic acid, succinic acid, lactic acid, butandiol, etc (ref 1). 13C NMR has been used to determine the aunthenticity and degree of adulteration (ref 2) as well as the length of the ageing process that a given sample has undergone. Also the formation of glucose and fructose acetates during maturation and ageing has been studied by 1H and 13C NMR.

Refs.
1) Caligiani et al., Anal. Chim. Acta, 585 (2007) 110-119
2) Consonni et al., Talanta, 75 (2008) 765-769
3) Consonni et al., Anal. Chim. Acta, 611 (2008) 31-40
4) Consonni and Caligiani, Talanta, 73 (2007) 332-339
5) Cirlini et al, Food Chemistry, 112 (2009) 51-56

The concentration and distribution of the organic components has been found to correlate well with ageing process analysis, identification of adulteration, and determination of authenticity of traditional balsamic vinegars and balsamic vinegars of Modena.
Below are a series of spectra showing what can chemistry can be quantified in the balsamic vinegars as well as a few comparative spectra of apple cider vinegar and malt vinegar.

For comparison with the home made ciders analyzed in the previous posting I am including the NMR of analysis of a commercial pear cider. The previous ciders were very dry while the pear cider was decidedly sweet. The carbohydrate content is a notable difference. The 1H spectrum is shown with chemical components identified.

There have been quite a lot of NMR studies centered around apple cider (non-alcoholic) and apple cider vinegar. However a search of the literature turns up no reference for NMR analysis of hard apple cider. This effort was undertaken to analyse the alcohol content of the ciders and to determine the malic and acetic acid content. Ciders were produced by Dr Tim McMahon of Orange Community College, NY….for his own consumption.

Below are the NMR spectra obtained by regular 1H acquisition and with BINOM solvent suppression.

Data was obtained on our Varian 300 MHz spectrometer. Samples were prepared by degassing followed by addition of 1 drop of D2O as lock solvent.

Process NMR Associates, LLC (Danbury CT) and Active Spectrum, Inc (San Carlos CA) are collaborating in the application of micro-ESR technology to petroleum applications. The initial work has focussed on crude oils but will soon be expanded to residues and cracker feedstocks.

Five samples of crude oil were tested by Micro-ESR spectrometry. The samples were:

1. Vasconia, Magdalena Basin, Columbia (V=39 ppm)
2. Merey, Eastern Venezuela Basin, Venezuela (V=303 ppm)
3. Oriente, Oriente Basin, Ecuador (V=65 ppm)
4. Qua Iboe, Agbada Formation, Niger Delta (V=2 ppm)
5. Basrah Light, Zubair Zone, Iraq (V=29 ppm)

The following spectra were observed:

Figure 1: Micro-ESR Spectra of Crude Oil

The central peak is a combination of a persistent carbon-centered organic radical (g = 2.003) found in asphaltenes, and a vanadyl (VO2+) peak. The additional smaller peaks are associated with vanadyl only.

For producers, the technique could be used to rapidly measure asphaltene concentration on-line. The spin density of the organic radical is a function of the maturity of the oil and will of course vary between deposits. Notwithstanding, rapid electronic measurement of asphaltenes remains a topic of great interest. Similar techniques have also been used to assess the quality of coals. For refiners, vanadium is a contaminant that poisons the refinery catalyst. ESR has been used by refiners since 1962 to rapidly measure vanadium content in crude oil feedstocks both on-line and in laboratories. Active Spectrum Inc.