Written by Gerard Rozing
This meeting was organized under the auspices of the Section Analytical Chemistry of the Royal Netherlands Society of Chemistry (KNCV) by Cari Sänger-van de Griend of Kantisto BV and Rawi Ramataur, of the Division of Analytical Biosciences at Leiden University on April 26, 2013. The meeting program was jointly arranged with the Section Analytical Chemistry of the Royal Belgium Society of Chemistry (KVCV) with Yvan van der Heyden and Debby Managelings, of the Department of Analytical Chemistry and Pharmaceutical Technology of the Free University of Brussels, and Ann van Schepdael of the Drug Analysis Group at Leuven University. AVANS+ an advanced training institute in The Netherlands hosted the meeting under local responsibility of Nico Vonk.
This CE-User Group Meeting was sponsored by Agilent Technologies, Beckman-Coulter, Prince Technologies and Analis who provided information about products and services at small booths. Several posters were displayed in the exhibition and break room and on the alleys. 73 users from the Netherlands and the Flamish part of Belgium attended the meeting. All talks were in English The meeting took place for the 3rd time.
Following oral program was offered:
|Yannis François (Université de Strasbourg)
||Simultaneous peptide mapping, posttranslational modifications and major N-glycosylation characterization of mAbs therapeutics by sheathless CESI-MS/MS
|Iulia Oita (Vrije Universiteit Brussel)
||Sample matrix influence for poliovirus CE separation
|Ewoud van Tricht, Crucell Holland BV, a Johnson & Johnson company
||CE for vaccine analysis
|François de l’Escaille (Analis) en Cari Sänger (Kantisto BV en Uppsala Universitet)
|Carolin Huhn (Forschungszentrum Jülich)
||Multidimensional separation using column-coupling ITP-CE-MS
|Robert-Jan Raterink (Universiteit Leiden)
||Sample preparation by 3-phase electroextraction
|Chen Hui (KU Leuven)
||Applications of CE in enzyme inhibition assays
|Rob Haselberg (Vrije Universiteit Amsterdam)
||CE-based assessment of protein affinity and purity
Following are my personal impressions of the talks and notes about the meeting.
From the attendance and the discussions around the talks, at the breaks and with the vendors, it can be easily concluded that in these parts of Europe CE is strong and exploring new paths for solving difficult problems in life science research.
In the first talk by Yannis Francois the advantages of using CE in the characterization of mAb therapeutics. Despite the limitations of CE like the low sample volume, the compliance of background electrolyte with vacuum detection in MS and difficulties to maintain the electric field as he mentioned, eventually he showed to obtain sensitivity comparable with nanoLC-MS. In particular he emphasized the strong increase in ESI-MS with decrease of hydraulic flow rate below 50 nL min. He used the Beckman CESI with a Bruker microTOF QII and emphasized the advantage of having a common ground between CE-current and electrospray current. Noticeable though was the application of pressure on the inlet vial to sustain flow towards the end of the CE capillary. He claimed that the 180x30 µm capillary with the porous tip worked reliable in his hands. Interesting to notice too was the fact that he worked at medium field strength (20KV). This was necessary to allow the MS time for data acquisition. In general one should realize that the absence of a gradient mode in CE, the window of separations is smaller that in nanoLC. The very high efficiencey of the peaks in the window is demanding for MS.
Using CE in the characterization of viruses was the focus of the talks by Julia Oita and Ewoud van Tricht highlighted different aspects of this work. Oita's talk dealt with separation of the whole virus particles. In van Tricht's talk on the influenza virus the focus was on fast separation and quantitation of the four essential proteins within the virus particle. SDS Capillary Gel Electrophoresis solved their problem and allowed automated analysis of many samples.
In the troubleshooting session Cari and Francois de l'Escaille presented two practical case stories which raised an intensive discussion amongst the participants and resulted in good suggestions for the submitters of the problem cases.
Carolin Huhn gave an impressive account of her recent work in 2-dimensional CE. They developed a new capacitively coupled contactless conductivity detector (C4D) with a very small sensor which allowed to monitor the first dimension separation. To couple the different CE capillaries a chip based device was constructed allowing different fluidic paths as required.
An original approach for sample preparation was presented by Robert-Jan Raterink. In an Eppendorf vial the aqueous sample, e.g. serum was put at the bottom of the vial. The aqueous sample was covered with a non-miscible layer of an organic solvent. A dispensing pipette was entered into the organic solvent an a small droplet of an aqueous solvent was expirated at its tip. A electrical field was applied between the two aqueous areas. The small solutes move from the lower aqueous layer into the upper droplet. Proteins and other large biomolecules in the serum sample will not move through the organic layer. Though putatively simple the approach raised some questions. Obviously some solubility of the solutes in the organic layer is mandatory. On the other hand, solutes with some hydrophobicity may stay in the organic layer because of a more favorable distribution coefficient. It was also pointed out the the pKa of the solutes may change strongly so that they may loose their charge. To my opinion a clever idea which requires more investigation.
Overall a very valuable event for all participants. Especially the troubleshooting session has enlighted the program very much. An event to put on one's agenda when one is involved in CE.