PCA200 - entry level pK_a & logP titrator

Ag/AgCI, double junction reference

Overhead, variable speed

PT100, allows automatic temperature compensation

Acid and Base, minimum of 0.4µL with 5mL syringe

Two quartz dispenser tubes

Fully automated X-Y axis

Two water washes and one special wash station provided

Two pH7 buffer positions, one storage and one calibration

Glass temperature control vessel (external circulating bath required)

Nitrogen or argon required

Supports 7 including Octanol and a generic solvent

Supports 10 including MeOH and DMSO

Liquid-crystal 16-line display for text and graphics, 22-buttons for numeric data entry

Sirius Four-Plus(TM) procedure

>0.5 mM (depending on the pH range)

1.8 - 12.2

Minimum 5mL, maximum 20mL

Supports D-PAS

One mains power inlet (110 or 240 V)

Cable from PCA200 to PC serial comm port

Windows 2000 or XP

PCA200 Firmware Version 2.107. RefinementPro Version 2.0.1.1

See 'pH-metric reagents' sheet

600 x 440 x 520mm (WxDxH)

25kg

900 x 800 x 750mm (WxDxH)

Pentium processor Minimum 128 MB RAM Hard disk, CD ROM, floppy drive

1024 x 768 screen display One free PCI expansion slot for data collection card (for D-PAS if required later) of size 175 x 110 x 15mm (LxWxH). Graphics card that supports OpenGL One free serial port

Cable to serial port (no limit to length)

Pentium processor Minimum 128 MB RAM Hard disk, CD ROM, floppy drive

1024 x 768 screen display One free PCI expansion slot for data collection card (for D-PAS if required later) of size 175 x 110 x 15mm (LxWxH). Graphics card that supports OpenGL One free serial port

Cable to serial port (800mm maximum length) Note: hence the PC must be next to the D-PAS

Cable to serial port (no limit to length)

Attaches to the left side of the PCA200 and via-dip pro

Width 780mm
Depth 440mm
Height 660mm

This excludes the space required for the PC and printer

PCA200 has only two dispensers so the ISA water, partition solvents, and co-solvents must be added manually. The volumes added have to be accurate so it is recommended to use positive displacement pipettes, e.g. Eppendorf, which have disposable tips. To cover the range of volumes required, use two variable volume pipettes, i/ 20µL-200µL and ii/500-5000µL

Set-up a constant temperature circulator that will supply temperature controlled water to the PCA200 temperature control unit. Sirius will supply two connectors that fit tubing with an internal diameter of 5mm. The customer is required to supply suitable tubing to fit between these connectors and the water circulator. Ensure that the circulator is below the height of the bench on which the PCA200 will be sited.

A suitable specfication is:

5-80°C +/-0.1°C
2 psi free flow pressure
Maximum pressure when outlet is blocked 10 psi
4L capacity
Cooling rate of 1 degree per 2-3 minutes

The customer is required to make up the following reagents:

This water is used for making up reagents and for rinsing. It should be freshly distilled or de-ionised, or purchased (e.g. HPLC-grade). The resistivity of the water should be more than 10MW cm.

Volume required: 4L
This solution is distilled or deionised water with its ionic strength adjusted by the addition of inert "background electrolyte" salt. This ISA water is used as the matrix for all the titrations.

Volume required: 1L
We suggest that customers purchase this ready-made as a volumetric standard. Check that the solution does not contain mercury salts or other additives. Sirius recommend Aldrich 31,895-7 05027N HCI solution.

Volume required: 1L
Must be made from CO2 -free ampoules of KOH solution. Do not use flakes or pellets of KOH, or ready-made volumetric standards, as these forms of KOH usually contain significant amounts of CO2-. The Sirius applications laboratory uses ampoules containing concentrated KOH solution. Suitable ampoules are supplied by Fisher and Merck. The KOH solution should not be stored in a glass container after preparation because KOH slowly dissolves silica from the glass, which interferes with pK_a determinations.

olume required: 1L
The partition solvent most commonly used is octan-1-ol (C8H17OH) which is the default partition solvent when GLpKa is installed. The octanol should be "water-saturated" (this can be done at the time of installation). We recommend "partition-grade" octanol.

Up to four CoSolvents can be connected to the 4-way valve. The customer should supply 1L of 80% methanol at the time of installation. Additional solutions can be made up during or after installation. To make up 80% methanol, weigh 11.18g of KCI, dissolve in 200mL of water and add methanol to make volume up to 1L in a volumetric flask.

Volume required: 1L
This is a 0.5% solution of Triton X-100 in water. Dissolve 5mL of Triton X-100 in 1L of water. (Triton X-100 is a Registered Trademark of Rohm and Haas)

Weight required: 100g
High purity crystalline solid used for standardising base titrant.

Used to recharge the CO2 absorption tube which is fitted to the KOH reagent bottle.