The efficient urea analyzer
Ureakvant 4 is automatic analyzer evaluating the urea content in full-fat milk. Plate-shaped magazine bearing the milk samples, calibration solutions and check sample will be placed into the analyzer. After the switch on of analysis all series will be measured automatically. The control of the analysis quality is implemented to the analyzer control program. Communication with the operating staff is provided by the dialog boxes.
UREAKVANT 4 is controlled by an external PC, attached to it through a bunched cables. The communication is performed by keyboard and printer attached to the control PC. The computer, printer and analyzer itself are connected by separate cables to the » 220 V system voltage. The results output is indicated on the display by a running information about the current state and on the printer. The printing of the results can be selected as running or overall one. It is also possible to save the results on a floppy disk, so that they can be used for further processing.
The analyzer is mounted on a metal chassis, which bears all the electromechanical components. The analyzer housing is plastic with removable sides. The vessel with a diluting solution is located in the space underneath the left part of the analyzer. The measuring cell (biosensor), the fluid mechanics, e.g. peristaltic pumps and magnetic valve are located in the space underneath the right part of the analyzer. The rear side of the analyzer bears the connector for the hose leading to the waste container. The upper side of the analyzer has a hole to insert 60 positions carousel with samples. Another six separated holes for the micro-tubes with the check samples and standards are located on the left upper side of the analyzer. Vertically and horizontally movable arm carrying the well point is located approximately in the middle of the analyzer.
1.2. The object
The characteristics of the analyzer, such as the simple operation, minimal maintenance, auto-control of the analysis correctness, the high speed (up to 80 samples an hour) and the ability to run on the stand-by mode, determine the analyzer for the routine operation in central laboratories engaged in milk analyses.
UREAKVANT 4 is intended to a routine evaluation of the urea concentration but only in full-fat milk. The native breast milk or even preserved milk samples could be analysed. The permitted preserving reagents are: bronopol, natamycin, streptomycin and other antibiotics, sodium azide, potassium two-chroman. The preserving reagents on salt or heavy metal complex, esp. mercury and silver, bases could not be used.
1.3. The analysis principle
The analysis principle is derived from the function of an enzymic conductive biosensor the analyzer is equipped with. The biosensor is located on the right side of the analyzer underneath the hinged side cover. It consists of a diluting chamber, a tempering block, two massive flow-through electrodes and the enzymic reactor chamber equipped with a hinged transparent plastic cover.
The process of the analysis begins with the well point that takes off 40 ml of the sample, the sample is put into the diluting chamber in the measuring cell. In there the sample is diluted and tempered. The diluted sample is then sucked by the peristaltic pump through the tempering block and enzymic rector. After chemical and electrical actions being stable the suction is stopped. In this phase the products of the urea enzymatic hydrolysis accumulate in the enzymic reactor. The urea hydrolysis is catalysed with the urease enzyme that is present in the reactor internal active layer. The products of the urea hydrolysis cause the increase in the reactor electric conductance. The speed of this increase is proportional to the urea concentration in the sample. This fact is valid provided that the chemical properties of the diluting solution, standards and check samples are mutually adjusted and match the electric scanning and measured data processing.
The first installation of the UREAKVANT 4 analyzer must be carried out by the supplier. Shall the apparatus be moved to another working site it is recommended that the supplier would be asked for the re-commissioning. After the installation and the switch on of the microcomputer and analyzer the autotest of all servo components will take place and the analyzer sets itself on a stand-by mode. The analyzer emerges itself in the dialog box of the display with the report on the actual analyzer performance.
2.1. Working site
The UREAKVANT 4 analyzer must be installed in sufficiently ventilated rooms. The best location for the analyzer is a vacant area of 120 x 80 cm. The voltage system supply 220 V / 50 Hz (electric installation according to the standards of ÈSN) must be within the reach of the analyzer. The working place must not be exposed to the impact of direct sun rays. The ambient temperature must be in the range of 15 - 32°C. The working place must be free of stain or spill risks.
2.2. Diluting solution
During the installation or in case of the faults notification "Chybí øedicí roztok (Diluting solution missing)" the left side plate must be lifted and the cap of the plastic bottle with the suction pipes must be taken away. The bottle shall be taken away as well and re-filled with a washing solution or be replaced by a new one. After re-filling the bottle must be put in to its original position and the cap with the suction pipes be put on it.
A plastic canister can be used as the waste container. It should be placed underneath the working place. The wide-mouth waste vessels, i.e. buckets etc., are not permitted by hygienic provisions. When discharging the waste container content the hygienic provisions and appropriate working site instructions must be followed.
2.4. Enzymic reactor
The installation and replacement of the reactor must be carried out according to the following procedure. In the menu switch on the program "vyprázdnìní systému (discharging of the system)". When finished the program switch the analyzer off. Lift the left side plate of the analyzer. Remove the transparent plastic cover from the measuring cell. With the index-finger move down the release lever and remove the old reactor. With a silk cloth soaked in a distilled water wipe off the contact surfaces of the reactor in the measuring cell and dry them up. Assure there would be no impurities on the contact surfaces or in the inlets and outlets for samples. Remove the new reactor from the packing, clean its rubber sealed contact surfaces with a silk cloth and move them round slightly. Tighten the release lever of the measuring cell and insert the reactor full-depth into the tray between electrodes. Release the lever and check the position of the reactor. Close the measuring cell with the transparent plastic cover by pushing it on its original position up to a moment when it "clicks". Then close the right side plate of the analyzer. Switch the analyzer on and let it run in the stand-by mode.
2.5. Calibration solutions
Calibration solutions are provided in a set consisting of 5 milk samples with a known urea concentration. It is namely: 12, 24, 36, 48 and 60 mg of urea in 100 ml of milk. They must be kept in a refrigerator. Place the micro test tubes containing the calibration solutions into the separated holes located on the left upper side of the analyzer, so that the closest one will accommodate the micro test tube with the solution with a concentration of 60 mg/100 ml the next one 48 mg/100 ml and so on through the fifth one with 12 mg/100 ml. The calibration solutions are required for the first putting into operation, after the replacement of the reactor and any time when program "Calibration" is on. The start of Calibration program must always be authorized by the user. Shall the calibration process be false the dialog program will be activated.
If the micro test tubes containing the standards, placed in the analyzer, are not used immediately, they will have to be capped. Before we start the calibration the micro test tubes must be open again. Otherwise it would cause a damage to the well point!
2.6. Check sample
The check sample supplied by the manufacturer is a milk containing 30 mg of urea in 100 ml of milk. It must be kept in a refrigerator. Place the micro test tube containing the check sample to the furthest separated hole located on the left upper side of the analyzer, the one marked with a sign "STAT". The check sample is required before you start the sample analysis itself, at that there can only be 60 samples in one series (the number of positions on the carousel). If the check sample analysis is correct (the analysis result is within the range of 30 ± 3 mg/100 ml), the analysis of the diluted milk samples in micro test tube placed in the carousel will start automatically. Otherwise the analysis is stopped and the dialog program will be activated.
If the micro test tube containing the check sample, placed in the analyzer, is not used immediately, it will have to be capped. Before we start the calibration the micro test tube must be open again. Otherwise it would cause a damage to the well point!
2.7. Milk sample
The homogenised milk samples shall be poured or pipetted into the plastic micro test tubes supplied by the analyzer manufacturer. The micro test tubes shall be placed into the corresponding position in the carousel. The carousel will be put into the analyzer. The samples will be analysed in an ascending order so that each sample will be signed with a particular number, corresponding its position on the carousel. The vacant positions on the carousel will not be analysed. The analysis will end automatically if there is no other sample to be analysed.
3. analysis execution
The analysis mode can be switched on provided that the calibration has been finished. Before the start of the analysis make sure the printer is on and in the mode "Nastavení (Setting)" - the sign "Tisk povolen (Print permitted)" is switched. The analysis is performed in blocks, with up to 60 samples in one block. Each block (series) samples analysis starts with the analysis of the check sample and ends with the analyzer in the stand-by mode.
When the first putting into operation is carried out no data, enabling the milk sample analysis, are available. In this case the calibration is compulsory.
Place the micro test tubes containing the calibration solutions into the separated holes on the left upper side of the analyzer. Make sure they are correctly positioned and uncapped. Then start the calibration from the basic menu by pushing the key F2. Shall there be any fault in the calibration, the calibration should be carried out once again. If the troubles still occur you will have to check-out the quality of the calibration solutions being used (expiration, the type of storage). If you cannot detect the fault, you will have to wait for some hours (overnight) and than repeat the process once again. We warn the user of the fact, that the new reactor, or a low active reactor will probably require calibration more frequently.
When in the routine operation, the calibration shall be carried out only if the faults notification "Kontrolní vzorek mimo meze (Check sample out of range)" repeats more often. If the faults notification "Posun kalibrace (Calibration shift)" appears after the new calibration, you will have to carry out the calibration once again.
Place the micro test tube containing the check sample into the separated hole on the right upper side of the analyzer. Make sure the micro test tube is positioned correctly and uncapped. Put the carousel with milk samples into the analyzer. To start the analysis push the key F3 in from the basic menu. The check sample is analysed at first. If the result does not exceed the appropriate range all series of the samples on the carousel will be analysed automatically. If the result is out of the range the analysis will be stopped. The operator will decide whether to continue the analysis or to stop it. Although it is possible to continue the analysis even in these conditions, we recommend to stop it and carry it out once again with a new check sample. If the faults notification "Kontrolní vzorek mimo meze (Check sample out of range)" repeats more often, you will have to carry out a new calibration and then return to the analysis itself.
3.3. End of measuring
At the end of a work day it is advisable to wash through the fluid ducts of the measuring cell by using the program "Promytí (Wash)". It is advisable not to switch off the apparatus through all the work week. You can switch it off at the end of a work week.
The analyzer is designed not to require any special maintenance. Yet it is necessary to follow some instructions to avoid malfunctions or faults.
4.1. Replacement of enzymic reactor
After app. 10 000 analysed samples or 2 months operation the reactor losses its activity. This might be recognized by an increase in a number of faults notifications. Therefore the reactor must be replaced when any of the conditions mentioned above occur.
4.2. Removal and cleaning of the well point
The removal and installation of the well point must be carried out only when the analyzer is off. Pull the movable arm, bearing the measuring cell with the well point, up to its upper stop. Disconnect the well point hose connection. Unbolt the holding screw and lift the well point. The installation of a new well point must be carried out the other way round. Clean the well point with a thin steel wire.
Cleaning of the fluid ducts of the measuring cell (biosensor) is necessary when the system is slightly or totally clogged up. This activity is to be performed by a service staff.
4.3. Replacement of a pump hose
The pump hose should be replaced after app. 1000 hours in operation. Turn the lock on the upper side of a pump for 90°. Take out all the hose segment. Take the hose out of the groove and place the new one. Put back the segment and lock it.
4.4. Movable parts
Some movable parts, e.g. the indented belt, the gearbox, must be checked-out after 2000 hours in operation. These activities must be carried out by a service technician since the apparatus housing must be removed during the check-out.
4.5. Safety regulations
The apparatus should be used only for an in vitro evaluation. All safety and hygienic regulations must be followed. The internal equipment may be adjusted only by a service technician.
5. guarantee conditions
The guarantee conditions are specified in the contract of purchase dated on:........ ........ ............., clause 12.
The manufacturer retains the right not to guarantee the defects demonstrably caused by a user: i.e. the fluid ducts clogged up with clots or mechanical impurities from the sample, defects resulting from any kind of violent behaviour or defects resulting from spill or other contamination that could have been prevented by operators.
AGROSLUŽBY Olomouc, s.r.o.
Střední Novosadská 55