Renewable Resources Robert-Jan van Putten,†,‡ Jan C. van der Waal,† Ed de Jong,*,† Carolus B. Rasrendra,‡,⊥ Hero J. Heeres,*,‡ and Johannes G. de Vries* †Avantium Chemicals, Zekeringstraat 29, 1014 BV Amsterdam, the Netherlands ‡Department of Chemical Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands DSM Innovative Synthesis BV, P.O. Box 18, 6160 MD Geleen, the Netherlands Department of Chemical Engineering, Institut Teknologi Bandung, Ganesha 10, Bandung 40132, Indonesia

Hydroxymethylfurfural, A Versatile Platform Chemical Made from Renewable Resources

5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications

Some Typical Advances in the Synthetic Applications of Allenes

Separation of polar compounds on polar stationary phases with partly aqueous eluents is by no means a new separation mode in LC. The first HPLC applications were published more than 30 years ago, and were for a long time mostly confined to carbohydrate analysis. In the early 1990s new phases started to emerge, and the practice was given a name, hydrophilic interaction chromatography (HILIC). Although the use of this separation mode has been relatively limited, we have seen a sudden increase in popularity over the last few years, promoted by the need to analyze polar compounds in increasingly complex mixtures. Another reason for the increase in popularity is the widespread use of MS coupled to LC. The partly aqueous eluents high in ACN with a limited need of adding salt is almost ideal for ESI. The applications now encompass most categories of polar compounds, charged as well as uncharged, although HILIC is particularly well suited for solutes lacking charge where coulombic interactions cannot be used to mediate retention. The review attempts to summarize the ongoing discussion on the separation mechanism and gives an overview of the stationary phases used and the applications addressed with this separation mode in LC.

Hydrophilic interaction chromatography.

Hydrophilic interaction liquid chromatography (HILIC) provides an alternative approach to effectively separate small polar compounds on polar stationary phases. The purpose of this work was to review the options for the characterization of HILIC stationary phases and their applications for separations of polar compounds in complex matrices. The characteristics of the hydrophilic stationary phase may affect and in some cases limit the choices of mobile phase composition, ion strength or buffer pH value available, since mechanisms other than hydrophilic partitioning could potentially occur. Enhancing our understanding of retention behavior in HILIC increases the scope of possible applications of liquid chromatography. One interesting option may also be to use HILIC in orthogonal and/or two-dimensional separations. Bioapplications of HILIC systems are also presented.

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Hydrophilic interaction liquid chromatography (HILIC)—a powerful separation technique

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Reaction of allenes with dichlorocarbene

Geometric isomers of fatty acids were separated by open tubular columns in SFC. The concentration of the analytes varied between 9 and 16 μg mL−1. Quantification of triglycerides with repeatability better than 20% were obtained in a home made SFE-SFC unit. A four point calibration curve for both trimyristin and tripalmitin was developed with correlation coefficients of 0.998 and 0.9998, respectively. The limit of quantification was approximately 3 ng for both components. Supercritical CO2 as extraction solvent in matrix containing lipids increased the recovery of cholesterol by a factor of three. Using immobilized lipase in on-line SFE-SFC quantification of cholesterol in spray dried egg yolk was possible.

Separation and Quantification of Components of Edible Fat Utilizing Open Tubular Columns in SFC. Sample Introduction by Direct Injection and SFE Coupled On-Line to SFC

The properties of sulphur dioxide as mobile phase in supercritical fluid chromatography have been examined. With neat supercritical sulphur dioxide polysiloxane and silica stationary phases were stripped from the columns and clogged the restrictors. The injector rotors needed frequent replacement and epoxy glued fused silica columns went to pieces. With a mixture of 20% sulphur dioxide in carbon dioxide, the problems were significantly reduced, but not completely. A series of columns were examined and all were eventually degraded, with the exception of a porous graphitic carbon column. The adsorptive properties of this material was too high, however, to be of any practical use with the SO2−CO2 mixture. The retention of polycyclic aromatic hydrocarbons as well as several other compounds was significantly reduced in 20% SO2 in CO2, compared to the retention in neat carbon dioxide, and good peak shapes were obtained before the columns became degraded. Before further progress can be made, however, capillary columns with stationary phases which can better withstand mixtures of sulphur dioxide and carbon dioxide are needed.

Sulphur dioxide as a mobile phase in supercritical fluid chromatography

A method for identification of proteins based on their pI values and peptide mass fingerprint (PMF) using an on‐line system has been developed. Proteins were separated by pH‐gradient strong anion exchange (SAX) chromatography and trapped on C4 reversed phase (RP) columns. Trapped proteins were on‐line transferred to an immobilized trypsin reactor, and the resulting peptides were subsequently on‐line transferred to an RP analytical column via a combination of RP and weak cation exchange (WCX) trap columns. The tryptic peptides were identified by electrospray ionization time‐of‐flight mass spectrometry (ESI‐TOF‐MS). Three model proteins were used for method development and basic human plasma proteins were subjected to identification. On‐column trypsination is compatible with high acetonitrile concentration. The analysis time was 180 min for the first fraction and an additional 80 min for each subsequent fraction selected for protein identification.

On‐line Method for Identification of Native Proteins using pH‐Gradient SAX Chromatography and Reversed Phase Chromatography‐Mass Spectrometry of Tryptic Peptides

In this paper, we describe approaches that make RP LC-SPE-NMR simpler, and in our opinion, result in more reliable methods for trapping and subsequent transfer of separated trace-level compounds to the NMR An SPE unit based on a commercially available, low dead-volume 10 port high-pressure column selector gives the possibility of trapping compounds on nine individual SPEs that have standard fittings This allows the operator to employ specific stationary phases that are not available as SPEs in commercially available LC-SPE-NMR systems Multiple trappings of small compounds like monuron, 1-(4-chlorophenyl)-3-methylurea, and 4-chlorophenylurea were easily performed employing a porous-carbon SPE material The system was optimized to elute the SPE-trapped compounds to the NMR probes in as small a volume as possible using back-flushing The proper match of NMR probe volume and SPE column inner diameter and elution volume was discussed, as well as the necessity of drying loaded SPEs prior to NMR transfer when using porous-carbon SPE material

Tyge Greibrokk

Papers

Reaction of allenes with dichlorocarbene

Separation and Quantification of Components of Edible Fat Utilizing Open Tubular Columns in SFC. Sample Introduction by Direct Injection and SFE Coupled On-Line to SFC

Sulphur dioxide as a mobile phase in supercritical fluid chromatography

On‐line Method for Identification of Native Proteins using pH‐Gradient SAX Chromatography and Reversed Phase Chromatography‐Mass Spectrometry of Tryptic Peptides

An alternative multiple-trapping LC-SPE-NMR system.