DV Series Sampling Probe, Bottom Only (1000mL)
This is a locking bottom and to be used with the DV Series Sampling Probe. Also used with CANTOP-DV
Cannula Assembly incorporates a unique Filter Assembly with a significantly increased capacity over the
Original Design, which is currently used in numerous Dissolution Labs. The New QLA Design also
incorporates additional significant improvements over the Original Design.
Problems associated with the Original Design:
- Capacity – The Original Design uses a small disc filter element which may clog prematurely afterpassing only a small sample volume. This is critical for methods that require multiple sample time pointsor large sample volumes which is often the case with UV analysis. Also, automated sampling systemscommonly require several ml of wash volume to eliminate carryover.
- Changing the filter element - The filter disc is installed flush with the end of the housing and can only beremoved with a tool.
- Back Washing – The original design incorporates a filter cap which is retained by a friction fit o-ring.The friction fit is not sufficient to handle the high pressure which is likely to occur during back washing.Back washing is a desirable method of extending the life of the filter element. Most autosamplingsystems may be programmed to perform backwashing.
Advantages of the New Design:
- Capacity – The “New Design” is a cylindrical shape with more than eight times the surface area than the“Original Design”. The new filter element is a well known dissolution filter which has been validatedon hundreds of dissolution methods world wide and is currently being used in numerous dissolutionlaboratories. This element is in high production and is readily available in 10, 35,45 and 70 microns.
- Changing the filter element – The filter element extends beyond the end of the filter cap and is easilyremoved without tools.
- Back Washing – The filter cap is locked on with a unique quick connect design which permits easyinstallation. This design permits the high back pressures encountered while back washing.
Materials of construction:
- Cannula – 316 Stainless Steel
- Filter Housing – Kynar (flouropolymer)
- O-ring – Silicone compound
- Filter Element – High Density Polyethylene
- Surface Area = .6767 in²
- Dead Volume = 0.5 ml
Components in the fluidic sampling path all contribute to the total hold up volume. Carryover tests are
typically conducted during method development so that adequate wash volumes may be employed to
eliminate hold up volume and to insure the integrity of the delivered sample.
Changing any of the components in the sampling path of existing methods should take into consideration
any potential change to the total hold up volume. Increases to the total hold up volume must be
accompanied by a similar change in the wash volume to maintain the integrity of the delivered sample.
Due to the larger capacity filter element, the “New Design” cannula has approximately 0.5 ml more hold
up volume than the “Old Design” cannula. When replacing “Old Design” cannula with “New Design”
cannula in existing methods, the wash volume should be increased by 0.5ml at each sample time point.
The Case for Resident Cannula:
Resident Cannula offer important advantages over Automated Cannula which are automatically lowered
into the vessel at sample time point. Some of these advantages include:
- Simplicity of design – No moving parts to potentially fail and no programming required for the cannulato enter the vessel. Also, changing from 900 to 500 ml media volume is a simpler task for the ResidentCannula.
- Lower initial cost – Automated probes are stepper motor driven and software controlled and thereforeadd a great deal of complexity and expense to the cost of the Dissolution Bath. Automated Cannula alsorequire more maintenance than Resident Cannula.
- Model: CAN1KBM-DV
- Manufactured by: QLA