Schmidt & Haensch are a leading German manufacturer of inline refractometers.

Monitoring peptide synthesis
How to monitor peptide synthesis in SPPS with refractive index measurement

​Peptides are short chains of amino acids that are commonly used to build the basis of many drugs on the current pharmaceutical and cosmetic market.

Most peptides are synthesized using solid-phase peptide synthesis (SPPS) in smaller or larger scales. How can this process be monitored to control the process in real-time? The refractive index (RI) of a liquid provides key information about its physical properties and the composition of any solution. Recently published papers show that RI measurement can be used as a process analytical tool (PAT) suitable for real-time monitoring of solid-phase peptide synthesis (SPPS). In SPPS protected amino acid derivates are successively added to a growing peptide chain that is immobilized on a solid phase. After adding the protected amino acid to the solid phase, it is deprotected and unreacted groups and side products are removed with washing steps. Afterwards the process is repeated to add further amino acids to the chain.

Studies have proven that all these steps can be monitored in real-time by measuring the refractive index. As the refractive index varies in the function of the amount of mass dissolved in the liquid this tool can be used to monitor the solid-phase peptide synthesis in real-time. Solid-phase peptide synthesis can be carried out in small laboratory or larger production scales. Both processes can be monitored using Schmidt+Haensch refractometer.

Smaller laboratory scale: To monitor the SPPS in small laboratory scales we recommend the VariRef laboratory refractometer.  Small scale process measurement is possible with a flow through sample compartment door and a membrane pump.
​Larger production scale: To monitor SPPS in larger production scales we recommend to use the process refractometer IPR-FR2. This refractometer can either be used at-line or even in-line. Together with our bypass solution including bypass, hoses and rack it ensures a high quality process at-line monitoring of the SPPS process. However it can also be integrated directly into the pipeline or the production reactor.

​Contact us for more information on: 01442 876 777 or email: [email protected].

Specification

Measuring scales: Ethylene Glycol (EG) Scale % wt.
Measuring range: 0 - 55 % wt.
Resolution: 0.1 % wt.
Accuracy: ± 0.3 % wt. at 10-30°C and within EG range of 0-5% wt.; 2 % wt. at 0-50°C and within EG range of 0-55% wt.
Operating temperature: - 10... +50 °C
Process pressure: max. 4 bar
Interface: RS485 Modbus
Dimension: 45mm x Ø 40mm
​Weight: approx 250g

Applications

Ethylene glycol is an industrial compound that is used in antifreeze, coolant for engines, airplane de-icing, heat transfer agents, conditioning agent in adhesives, cork, fibers, films, synthetic rubber, cellulose sponges, printing inks, and paper products. Ethylene glycol is also used in the dehydration of natural gas as well as in the production of alkyd-type resins and unsaturated polyester resins. Ethylene glycol is a colorless, odorless, moderately viscous, hygroscopic liquid with a sweet taste (toxic!).

The growing number of large-scale air-conditioning systems that contain a large amount of heat transfer liquid (mainly ethylene glycol) require constant surveillance. This surveillance can be done automatically and in real-time with the S+H iCS-EG.

Below are the key applications where this sensor excels:
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• HVAC systems
• Industrial cooling / heat exchange systems
• Ground source heating
• Data centers
• Chemical and manufacturing processes

With this inline sensor, maintenance of cooling systems can be reduced and hazardous leakages in the heat exchanger system can be detected early to prevent environmental pollution.

​​Contact us for more information, brochures or a free, no obligation quote on: 01442 876 777 or email: [email protected].