US PATENT SUBCLASS 436 / 177
.~ Liberation or purification of sample or separation of material from a sample (e.g., filtering, centrifuging, etc.)

Current as of: June, 1999
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436 /   HD   CHEMISTRY: ANALYTICAL AND IMMUNOLOGICAL TESTING

174  DF  INCLUDING SAMPLE PREPARATION {6}
177.~ Liberation or purification of sample or separation of material from a sample (e.g., filtering, centrifuging, etc.) {1}
178  DF  .~.~> Including use of a solid sorbent, semipermeable membrane, or liquid extraction

DEFINITION

Classification: 436/177

Liberation or purification of sample or separation of material from a sample (e.g., filtering, centrifuging, etc.):

(under subclass 174) Processes in which the sample to be subjected to chemical analysis is the product of an isolation or purification procedure.

(1) Note. Included herein are procedures involving

filtering, centrifuging, sorption, as well as concentrating evaporation and chromatography.

SEE OR SEARCH CLASS

34, Drying and Gas or Vapor Contact With Solids, provides for processes of separating liquids from solids or slurries, i.e., drying as well as the contact of solids with either, or both, gases and vapors. If the starting material is in the form of a liquid suspension or solution even if the process is continued to the point of complete dryness, Class 159, Concentrating Evaporators, will take the process.

62, Refrigeration, includes processes which include removing heat by refrigeration from a substance whether solid, liquid, or vapor. In particular, Class 62,

8+, will take processes of making a solidified or liquefied gaseous product provided the gas has a normal boiling point below 32 (methane, ethane, propane) and Class 62, subclasses 500+ will take processes wherein a solution or mixture is cooled to solidify a constituent which is then removed from the mixture.

95, Gas Separation: Processes, for physical processes involving steps resulting in separation of a gas from a fluid mixture comprising (a) a gas and solid or liquid particles entrained therein, (b) a liquid and gas entrained therein, or (c) a plurality of gases. 159, Concentrating Evaporators, provides for processes peculiar to the concentration of solids held in solution or suspension by evaporation of the liquid containing them and the recovery of the concentrate. If the starting material is a solid or slurry placement in Class 34, Drying and Gas or Vapor Contact With Solids, would be indicated. Class 159 will take concentration to the point of crystallization or to dryness, however, removal of water of crystallization is considered to be a chemical reaction and placement would not be proper in Class 159. Evaporating with subsequent vapor condensation is excluded from Class 159 and in such case, placement in Class 203, Distillation: Processes, Separatory, would be proper.

201, Distillation: Processes, Thermolytic, provides for processes of thermolytic distillation wherein a solid carbonaceous material is heated to vaporize a volatile portion and to cause chemical decomposition of the heated material to form different chemical substances at least some of which are volatile and leave behind a solid carbonaceous material.

203, Distillation: Processes, Separatory, provides for processes for separating a liquid mixture by vaporizing and condensing a portion thereof to isolate in the condensed liquid or the unvaporized portion a relatively pure compound which was present in the original mixture. The original

mixture may be in a solid form so long as it melts to form a liquid before it vaporizes. A solid original mixture which undergoes chemical decomposition leaving a carbonaceous residue would be classifiable in Class 201, Distillation: Processes, Thermolytic, which is superior to Class 203. Processes including a chemical reaction and a separatory distillation operation are classified in Class 203 only when the chemical reaction merely facilitates the isolation by the separatory distillation operation of a pre-existing substance in the distilland. See Class 260, Chemistry of Carbon Compounds, or Class 423, Chemistry of Inorganic Compounds, for a process of preparing a compound and isolating it by a separatory distillation process.

210, Liquid Purification or Separation, includes processes for the separation or purification of a constituent from a flowable liquid mixture by dialysis, sorption, ion exchange liquid extraction, gravitational separation, or filtration, as well as purification of a liquid mixture by destruction or conversion of a constituent. Processes directed to the purification of a particular compound or composition (including solution of either the compound or composition in water), are classified with the particular compound or composition. Insofar as the treatment of liquids with ion exchange or sorption materials are concerned, the following lines will be maintained. (1) Where water is the only disclosed liquid purified, the patent will be classified in this class (210). (2) Where disclosure includes water, hydrocarbons and/or other liquids the patent will be classified: (a) In Class 210 if all claims are broad as to the liquid. (b) In Class 210 if several species of liquid are claimed and one species includes water. (c) In the appropriate art class if some liquid other than water is the only liquid claimed (e.g., mineral oils, organic compounds). (3) Purification or separation of liquids by flocculation only are classified in Class 210. (4) Processes wherein all claims are limited to the deposition of specific materials on ion-exchangers or sorbents with subsequent recovery of the specific materials are classified with material so operated upon. Class 210 is superior to Class 95 and takes separating processes, per se, generally disclosed or claimed as fluid separation, or if the disclosure or a claim is restricted to liquid separation.

260, Chemistry of Carbon Compounds, provides for the liberation and purification by chemical or physical means of compounds and extracts falling within the class definition of Class 260. Generally the physical processes included are of two types (a) a purification process prior or subsequent to a chemical reaction producing a Class 260 product, (b) a purification process directed to the purification of a Class 260 compound by a combination of physical separation techniques the classes for which do not provide for or exclude the combination claimed. Chemical purification processes are generally provided for with each product produced.

422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing,

101, for apparatus for carrying out the process of this subclass.

435, Chemistry: Molecular Biology and Microbiology,

262+, for methods of using microorganism or enzyme to liberate or purify a preexisting substance.