Parr Instrument Company manufactures a range of sample preparation devices for procedures where the method requires a pressure vessel.  This is either to contain the vapour pressure generated by the heated mixture or any non-condensable gas that is required for the procedure.

Hydrothermal Synthesis

Many sample preparative techniques require an aqueous mixture to be heated above 100degC thus the system has an associated vapour pressure.  Popular examples of this are nanoparticle and zeolite synthesis.  Many of these methods also require either acid or alkaline conditions where stainless steel would be readily corroded.

Parr Instrument Company manufactures a range of pressure vessels that completely encapsulate the sample within a PTFE environment.  This PTFE cup and cover allows the pressure vessel to be manufactured out of the inexpensive material T316SS without the worry of corrosion or loss of sample.

These vessels can be heated up to 250degC and this is usually achieved by placing the vessels in a standard laboratory oven.

The popular models for this type of work are shown in the table below.

Model No	Total Volume (ml)	Maximum liquid fill volume (ml)	Internal dimensions(Diameter x depth, cm)
4749	23	15	2.62 x 4.37
4744	45	29	2.64 x 9.50
4748	125	82	4.45 x 8.25

More details of these vessels can be found by downloading both the sales literature and instruction manual.

Acid Digestion

Using Parr Instrument Company’s acid digestion vessels it is possible to dissolve certain inorganic and organic samples in mineral acids at elevated temperatures.

This can be done with either metal vessels with a PTFE liner heated in a conventional oven or vessels made from a high strength polymer that is heated in a microwave oven.

More info about these vessels and the technique can be found in the sales literature and respective operating manuals.

Oxygen Combustion

For many years an accepted method for the conversion of solid and liquid sample into a soluble aqueous form suitable for chemical analysis has been through the use of a Parr oxygen bomb.

An organic sample such as coal, is burnt in a 100% oxygen atmosphere at elevated pressures. This ensures complete combustion and all of the carbon and hydrogen are converted to CO₂ and H₂O respectively.  Other elements are then dissolved in a small volume of water that is placed in the vessel prior to combustion.

The oxygen combustion bomb is used in the following ASTM methods

ASTM Method D129-91, “Standard Test Method for Sulfur in Petroleum Products (General Bomb Method)”.

ASTM Method D3177-89, “Standard Test Method for Total Sulfur in the Analysis Sample of Coal and Coke”.

ASTM Method D2361-91, “Standard Test Method for Chlorine in Coal”.

ASTM Method D1619-88, “Standard Test Method for Sulfur in Carbon Black”.

ASTM Method D808-91, “Standard Test Method for Chlorine in New and Used Petroleum Products (Bomb Method)”.

ASTM Method D1847-87, “Standard Test Method for Total Chlorine Content of Epoxy Resins”.

ASTM Method D3684-78, (1988) “Standard Test Method for Total Mercury in Coal by the Oxygen Bomb Combustion/Atomic Absorption Method”.

ASTM Method D3761-91, “Standard Test Method for Total Fluorine in Coal by the Oxygen Combustion/Ion Selective Electrode Method”.

ASTM Method D4208-88, “Standard Test Method for Total Chlorine in Coal by the Oxygen Combustion/Ion Selective Electrode Method”.

ASTM Method E144-64, (1992), “Standard Recommended Practice for Safe Use of Oxygen Combustion Bombs”.

ASTM Method E775-87, “Standard Test Methods for Total Sulfur in the Analysis Sample of Refuse-Derived Fuel”.

ASTM Method E776-87, “Standard Test Method for forms of Chlorine in Refuse-Derived Fuel”.

ASTM Method E926-88, “Standard Test Method of Preparing Refuse-Derived.

These vessels are at the heart of our range of combustion calorimeters where the heat liberated is measured to determine the calorific value of the sample.

More information about these vessels and techniques can be found by downloading the sales literature and operating manual.

If you are unsure which model best fits your needs just Contact Us to speak to a specialist.

Please also visit the Parr Website for further information: