GB1149382A - A process for evaluating a property of a plurality of chemical substances - Google Patents

Abstract

1,149,382. Sampling liquids. JOYCE, LOEBL & CO. Ltd. 2 May, 1966 [7 May, 1965], No. 19305/65. Heading B8N. [Also in Divisions B1 and G1] The colour, density or concentration of treated biological samples is evaluated by a photo-meter, the initial samples being transferred individually and automatically from a first set of containers to a second set of containers, with the addition of one or more reagents, by means of one or more pipettes, and the prepared samples then being subjected to heat or centrifuge treatment (if this is required) before being passed sequentially through the photo-meter. In the illustrated embodiment, the various samples contained in tubes 6 are placed sequentially in an outer ring holder 7 which is located on the table 10 of rig. 1. Inside ring holder 7 is a ring holder 8 carrying sample receptacles such as 9 (rig. 2). A pipette 11 extracts a quantity of sample fluid from each tube 6 as the table 10 rotates step-by-step, and transfers the sample to the corresponding receptacle 9 together with a quantity of reagent or cleaning fluid from reservoir 16. An electric motor drives the table and the pump 13 for the pipette action. The apparatus for transferring samples from one set of tubes to another is described in detail, together with various modifications, in Specification 1,149,383. The holder 8 is next transferred to a centrifuge or oven and then placed in rig 2 for the addition of a further reagent to the samples by pipette 17, though sometimes this step may be omitted. In rig 3, supernatant or clear portions of liquid, free of sediment &c. are transferred from the receptacles 9 of the inner ring holder 8 to three of an outer ring holder 21, which is then transferred to rig 4. Here the samples are extracted in turn by pipette 26 for evaluation by the photo-meter 5. Photo-meter.-The photo-meter is described in detail in Specification 1,149,384. It is of the double beam type in which a photo-cell receives light alternately through the sample cuvette 30 and through a graduated motor-operated wedge, a servomotor receiving the output of the cell to move the wedge to equalize the two outputs and also controlling a pen 32 which records the transmissivity of the sample on a moving sheet 33. A first part of the sample is passed through the cuvette for washing purposes, then the rest for evaluation, the pen then being started one second after the evaluation liquid has been introduced, in order to avoid a misleading record. Digital information is printed on a moving sheet 35 and/or punch cards or tape may be produced carrying information as to the sample properties. Modifications.-Extra pipettes can be provided on the rigs to enable addition of more than one reagent or different reagents for different type of samples. Instead of refilling the single cuvette 30, samples may be introduced into individual cuvettes which are passed through the photo-meter sequentially.