Velp Scientifica UDK 139 Operating Manual
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Velp Scientifica UDK 139 Operating Manual

Semi-automatic distillation unit
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UDK 139
Semi-automatic Distillation Unit
Operating manual
Velp Scientifica thanks you for choosing the UDK 139 Semi-automatic Distillation Unit. The
UDK 139 is designed to perform nitrogen and protein content determination according to the
Kjeldahl Method (TKN) in the Food & Feed industry and has several other applications in
environmental control (nitrogen in water, soil and lubricants) and in the chemical and
pharmaceutical industry according to official AOAC, EPA, DIN e ISO procedures.
Safety warnings:
Before using the unit, please read the operating manual supplied with the apparatus
carefully.
Warning! Hot surface!
Do not dispose of this equipment as urban waste
This unit must be used for laboratory applications only.
The manufacturer declines all responsibility for any use of the unit that does not comply with
the instructions.
SAFETY PRECAUTIONS
In order to prevent the risk of electric shock, fire and personal injury when the unit is in use,
basic safety measures must always be taken including:
Ensure that liquids do not come into contact with the electric power cable or with the
electrical parts of the instrument.
Check that the power supply corresponds to the rating plate on the rear of the unit.
When replacing the power cable, make sure that the new cable has the same
characteristics as the original and that it is earthed.
Do not use the unit if it is not working correctly. In case of malfunctioning, contact your
nearest service centre.
The personal protective equipment must be compatible with the possible risks posed by
the material being processed and the glass of the containers.
The test tube reaches a temperature of 100°C during distillation and also during the
cooling phase. Use the pincer supplied to remove the test-tube at the end of distilling.
The vessels and the products used during the work-cycle must be compatible with the
temperatures reached by the unit (approx. 100°C).
For further information on the handling of the reagents see Chapter 2 "Chemicals".
Leave the transparent guard in place when the unit is running.
Follow the cleaning instructions described in this manual
The safety of the instrument is no longer guaranteed in the case of improper use or if the
instructions in this manual are not followed.
10004762/B5
1
188

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Summary of Contents for Velp Scientifica UDK 139

  • Page 1 Velp Scientifica thanks you for choosing the UDK 139 Semi-automatic Distillation Unit. The UDK 139 is designed to perform nitrogen and protein content determination according to the Kjeldahl Method (TKN) in the Food & Feed industry and has several other applications in environmental control (nitrogen in water, soil and lubricants) and in the chemical and pharmaceutical industry according to official AOAC, EPA, DIN e ISO procedures.
  • Page 2 Velp Scientifica – UDK139 Operating Manual RÈGLES DE SÉCURITÉ Pour éviter tout risque de choc électrique, incendie ou blessure corporelle pendant l'utilisation de l'appareil, toujours appliquer les mesures de sécurité de base, y compris les recommandations suivantes :  S'assurer que les liquides n'entrent pas en contact avec le cordon d'alimentation ou avec toute autre pièce électrique à...

  • Page 3: Table Of Contents

    CONTENTS 1.1. Parts included ......................6 1.2. Instrument description ..................... 7 2. Chemicals ......................10 2.1. Products used ....................... 10 2.2. Substances generated by digestion and distillation ..........11 3. Assembly and installation ..................12 3.1. Hydraulic connections ................... 13 3.2.
  • Page 4 Velp Scientifica – UDK139 Operating Manual 20. Analytical Methods ....................71 1 - Kjeldahl method to determine the protein content on milk and derived products ..71 2 - Kjeldahl method to determine the protein content on almonds, nuts, hazelnuts ..72 3 - Kjeldahl method to determine the protein content on coconuts ........
  • Page 5 Since its initial design, many improvements have been introduced aimed at reducing energy consumption, space requirements and sample quantities. The UDK 139 Semi-automatic Distillation Unit has a color touch-screen with electronic control for simple and user-friendly programming of parameters such as...

  • Page 6: Parts Included

    Velp Scientifica – UDK139 Operating Manual 1.1. Parts included Check that the unit is complete after unpacking. The table below shows the parts included: Description Code Q.ty UDK 139 Semi-automatic F30200130 Distillation Unit Test tube Ø 42 x 300 mm...

  • Page 7: Instrument Description

    The UDK 139 carries out all the stages of the distillation process such as the addition of single reagents and the removal of distillation residues automatically.
  • Page 8 GLP (Good Laboratory Practice).  The UDK 139 ensures the highest safety standards: it signals the absence of the test tube, test tube exchange at the end of analysis, safety guard open, the absence of reagents and the absence of cooling water.
  • Page 9 Velp Scientifica – UDK139 Operating Manual The UDK series guarantees unmatched savings whist ensuring an extremely high level of reliability. The UDK139 is exceptional in providing savings, by using TEMS technology: Time: Fast and frequent analyses; no heating delay between runs.

  • Page 10: Chemicals

    Velp Scientifica – UDK139 Operating Manual Chemicals 2.1. Products used The chemicals used for distillation and titration are potentially dangerous and must be handled with care and with personal protective equipment: gloves, goggles and pincer removal of the reaction hot test-tubes.

  • Page 11: Substances Generated By Digestion And Distillation

    Velp Scientifica – UDK139 Operating Manual 2.2. Substances generated digestion distillation 1) Sulphur dioxide and sulphur trioxide-containing fumes. During digestion with sulphuric acid the development of fumes occurs which contain mostly sulphur dioxide plus smaller amounts of sulphur trioxide. Both these gases are intensely irritating to eyes and respiratory tract, causing coughing and discomfort.

  • Page 12: Assembly And Installation

    Velp Scientifica – UDK139 Operating Manual Assembly and installation After unpacking the instrument position it on a laboratory bench or on a non- flammable surface at a distance of at least 30 cm from the walls so as not obstruct the air vents on the rear.

  • Page 13: Hydraulic Connections

    Velp Scientifica – UDK139 Operating Manual 3.1. Hydraulic connections Connect the tubes supplied to the tube holders located on the rear panel following the instructions below: INLET Cooling water inlet (tap water). Connect the unit to the tap water supply using the red and Cooling Water white tube with ¾”...

  • Page 14: Connection To The Electric Power Supply

    Velp Scientifica – UDK139 Operating Manual IMPORTANT  Place the carboys for the H O and NaOH solutions on the floor and not at the same level as the unit on the bench in order to avoid air locks in the suction tubes.

  • Page 15: Connection To External Devices

    Velp Scientifica – UDK139 Operating Manual 3.3. Connection to external devices The UDK 139 Semi-automatic distillation unit can be connected to various external devices useful for optimizing operator productivity, using the sockets on the rear:  Printer  Mouse 3.4.

  • Page 16: Mouse

    Velp Scientifica – UDK139 Operating Manual 3.4.1. Mouse A mouse with USB plug can be connected to one of the two USB ports to navigate the menus. Connect the mouse with the instrument turned on in order to activate the pointer.

  • Page 17: Using The Menus

    Velp Scientifica – UDK139 Operating Manual Using the menus 4.1. Quick Guide This page shows the instrument software. The purpose is to help the user identify the different possibilities offered by the instrument and how to reach them easily. ● Wash-down Analysis ●...
  • Page 18 Velp Scientifica – UDK139 Operating Manual ● Cal. NaOH pump ● Maintenance ● Clean NaOH circuit ● Clean filters ● Test tube connection ● N° analyses ● Service ● Upload software ● Advanced settings 10004762/B5...

  • Page 19: Main Menu

    Velp Scientifica – UDK139 Operating Manual 4.2. Main menu When the instrument is turned on, the display shows the name of the instrument and the software version for a few seconds. The main menu then appears: The yellow strip at the top of the display (present on every page of the software) indicates that preheating is in progress and shows the time left.
  • Page 20 Velp Scientifica – UDK139 Operating Manual In each sub-menu the arrow in the upper left corner allows you to return to the previous screen. 10004762/B5...

  • Page 21: Analysis

    Velp Scientifica – UDK139 Operating Manual 4.3. Analysis Select "Analysis" from the main menu: The sub-menus are shown below: To return to the main menu press the arrow in the upper left corner. 4.3.1. Wash-down During wash-down distillation is carried out using distilled water as a reagent in order to “wash”...
  • Page 22 Velp Scientifica – UDK139 Operating Manual To return to the “Wash down” menu press the arrow in the upper left corner. Pressing “Empty test tube”, it is possible to select or not the residues removing at the end of wash down, with “Yes” or “No”.

  • Page 23: Distillation

    Velp Scientifica – UDK139 Operating Manual The green flag on the right indicates that the phase was carried out correctly, a red X indicates that the phase did not terminate correctly. The blue line at the bottom of the display indicates the cooling water flow rate (e.g. Tap-water flow = 1.2 l/min).
  • Page 24 Velp Scientifica – UDK139 Operating Manual Press Sample name. The following window appears: Enter the sample name (max. 13 characters) using the alphanumeric keypad. Press to confirm. Press Q.ty of sample and enter the sample quantity using the alphanumeric keypad: Use the touch-screen to select the unit of measure required and press confirm.
  • Page 25 Velp Scientifica – UDK139 Operating Manual Use the alphanumeric keypad to enter notes and press to confirm. Press Confirm to confirm the parameter settings of the analysis. The following window appears: Position the test tube containing the sample in its seat and press...

  • Page 26: Methods

    Velp Scientifica – UDK139 Operating Manual Press or the "Distillation" arrow top left to print the analysis data (if automatic print-out has been selected) and return to the "Distillation" menu in order to with a new analysis. 4.4. Methods Select Methods from the "Main" menu.
  • Page 27 Velp Scientifica – UDK139 Operating Manual Press button to move to the next window. Press button to return to the previous window. NOTE: upon receipt of the instrument all customizable methods include default parameters entered by Velp. Use the touch-screen to select each parameter and modify the value.

  • Page 28: Set-Up

    Velp Scientifica – UDK139 Operating Manual 4.5. Set-up Select Set-up from the "Main" menu. The following submenus are listed: To return to the "Main" menu press the arrow top left. Press to move to the next window. Press to return to the previous window.
  • Page 29 Velp Scientifica – UDK139 Operating Manual Select Frequency and use the touch-screen to select the frequency of the power supply at the place of installation . Press to confirm. Select Keyboard sounds and use the touch-screen to select YES/NO to enable/disable the acoustic signal when touch-screen keys are pressed.
  • Page 30 Velp Scientifica – UDK139 Operating Manual Standard Compressed VELP SCIENTIFICA VELP SCIENTIFICA Distillator: UDK139 Distillator: UDK139 Software Version: 1.0.0 Software Version: 1.0.0 ______________________ ______________________ Date: Date: 20/09/2010 20/09/2010 Time: Time: 14.49 15.00 Laboratory name: Velp Scientifica Operator: Sample: Paolo Milk Q.ty sample:...

  • Page 31: System

    Velp Scientifica – UDK139 Operating Manual 4.6. System Select “System” from the main menu. The four sub-menus are listed: To return to the "Main" menu press the arrow top left. 4.6.1. Check-up Select Check-up from the "Main" menu. The three sub-menus are shown below: To return to the “System”...
  • Page 32 Velp Scientifica – UDK139 Operating Manual It is also possible check the correct functioning of safety devices, level sensors and the cooling water detector. NOTE: it is fundamental that all the checks are carried out during installation in order to fill the hydraulic circuits. Velp recommends the use of the automatic controls during this phase.
  • Page 33 Velp Scientifica – UDK139 Operating Manual To return to the “Check-up” menu press the arrow in the upper left corner. Press to start all the operations listed automatically. The green flag on the right indicates that the operation was carried out correctly, a red X indicates that the operation was not successful.
  • Page 34 Velp Scientifica – UDK139 Operating Manual Select Safety guard. The display shows: Press and follow the instructions on the display. The green flag on the right indicates that the operation was carried out correctly, a red X indicates that the operation was not successful.
  • Page 35 Velp Scientifica – UDK139 Operating Manual The green flag on the right indicates that the operation was carried out correctly, a red X indicates that the operation was not successful. The procedure can be interrupted at any time by pressing Press Safety lever.
  • Page 36 Velp Scientifica – UDK139 Operating Manual Select Inlet tube H O. The display shows: Press and follow the instructions on the display. The green flag on the right indicates that the operation was carried out correctly, a red X indicates that the operation was not successful.
  • Page 37 Velp Scientifica – UDK139 Operating Manual Press and follow the instructions on the display. The green flag on the right indicates that the operation was carried out correctly, a red X indicates that the operation was not successful. The procedure can be interrupted at any time by pressing Press the arrow top left to return to the "Diagnosis"...

  • Page 38: Calibration

    Velp Scientifica – UDK139 Operating Manual 4.6.2. Calibration Select Calibration from the “System” menu. The following sub-menus are listed: To return to the "System" menu press the arrow top left. The "Calibration" menu is used to calibrate the flow rate of the reagent pumps.

  • Page 39: Maintenance

    Velp Scientifica – UDK139 Operating Manual The procedure can be interrupted at any time by pressing NOTE: If you wish to double-check correct dosage after calibration, this should be done during a normal work-cycle since during calibration a theoretical volume of 50ml only can be measured.

  • Page 40: Service

    Velp Scientifica – UDK139 Operating Manual Select Cleaning of NaOH circuit from the “Maintenance” menu, the display shows: To return to the "Maintenance" menu press the Maintenance arrow top left. The following information is displayed: - Maintenance frequency. Maintenance is recommended every 500 analyses;...
  • Page 41 Velp Scientifica – UDK139 Operating Manual To return to the "System" menu press the arrow top left. Select Upload software. The display shows: The software can be upgraded by following a few simple, guided steps. Insert the USB pen drive containing the updated software file into the USB port of the instrument.

  • Page 42: Operating Controls

    Velp Scientifica – UDK139 Operating Manual Operating Controls 5.1. Safety devices, signals and warnings 5.1.1. Safety devices The instrument is equipped with various safety devices that can prevent start-up or interrupt a work-cycle to protect the operator and the instrument itself.

  • Page 43: Reserves And Overfilling

    Velp Scientifica – UDK139 Operating Manual 5.1.2. Reserves and overfilling Reserves An automatic warning system notifies the operator of low reagent levels during analysis. The external reagent tubes supplied with the unit are fitted with level sensors. The level sensors should be connected to the “Reserve” contact of the corresponding inlet connection on the rear panel of the unit.

  • Page 44: Warning Signals And Messages

    Velp Scientifica – UDK139 Operating Manual 5.1.3. Warning signals and messages Warning signals during the work-cycle Insufficient cooling water The unit is fitted with flow meter that measures the cooling water flow rate. If the tap has not been turned on or the tap water flow rate is too low: - when the instrument is turned on, the display shows "AL10.

  • Page 45: Black-Out

    Velp Scientifica – UDK139 Operating Manual 5.1.4. Black-out A power failure during analysis will result in the analysis in progress being lost. The previously entered analysis parameters will be retained. When the electricity is restored the unit will carry out preheating before starting analysis.

  • Page 46: Graph Of Tap Water Consumption Related To The Water Flow Rate And Temperature

    Velp Scientifica – UDK139 Operating Manual 5.3. Graph of tap water consumption related to the water flow rate and temperature The graph below shows the efficiency of the patented Velp titanium condenser compared to traditional glass condensers. It is important to underline how the new titanium condenser keeps the temperature of the distillate below the threshold value (35°C) indicated by the Kjeldahl method...

  • Page 47: Work Cycle

    Velp Scientifica – UDK139 Operating Manual Work cycle The unit can perform different types of analysis:  Analysis  Devarda’s analysis The steps involved for each method are shown below. 6.1. Analysis 1. Switch on the instrument using the ON/OFF switch on the rh side of the instrument;...

  • Page 48: End-Of-Work Operations

    Velp Scientifica – UDK139 Operating Manual 14. Start analysis. 15. An acoustic signal indicates that the work cycle has terminated. 16. Remove the test tube and replace it with a new sample. If distillation series has finished, place an empty test tube in the unit.

  • Page 49: Maintenance

    Velp Scientifica – UDK139 Operating Manual Maintenance The instrument is fitted with a cycle counter that alerts the operator through messages on the display when routine/extraordinary maintenance is required. The front panel (service door) of the instrument opens fully to allow easy and safe access to the internal parts in order to carry out the following operations: ...

  • Page 50: Extraordinary Maintenance

    Velp Scientifica – UDK139 Operating Manual 8.2. Extraordinary maintenance  Extraordinary maintenance operations not included in this manual and the servicing of internal parts, must be carried out by persons expressly authorized by VELP Scientifica.  In order to reduce the risks arising from contact with reagents or solutions, the use of suitable personal protective equipment (gloves, etc.) is recommended.
  • Page 51 Velp Scientifica – UDK139 Operating Manual The filters are found on the tap water inlet and on the reagent inlets: - Tap water inlet: remove the cooling water tube from the unit and pull the filter out using small pincers. Clean the filter under running water or using compressed air - Reagent inlets: the three reagent tubes with level sensors are fitted with filters located at the lower extremity.

  • Page 52: Operations To Be Performed Only When Necessary

    The fuses must only be replaced by qualified personnel and only with fuses supplied by Velp Scientifica Srl. To replace the fuses disconnect the unit from the power supply, unscrew the fuse caps located on the back of the unit.

  • Page 53: Expedients For Transport

    Velp Scientifica – UDK139 Operating Manual 8.3. Expedients for transport The instrument must be transported in its original packaging and any indications present on the original packaging must be followed (e.g. palletised). The caps must be placed on the hydraulic connections.

  • Page 54: Disposing Of The Unit

    Velp Scientifica – UDK139 Operating Manual Disposing of the unit For the temporary decommissioning always empty the tubes of reagents and solutions, sodium hydrate in particular, as described in "Expedients for transport”. The instrument is classified as electrical/electronic apparatus and must be disposed of accordingly.

  • Page 55: Spare Parts

    10006304 The above mentioned spare parts can be easily replaced by the operator. For other spare parts (and for the complete list) please contact Velp Scientifica Srl’s nearest Service Centre. * Replace the fuses only when necessary, i.e. if the unit doesn’t turn on and the mains switch does not light up.

  • Page 56: Technical Features

    Velp Scientifica – UDK139 Operating Manual Technical features GENERAL Power supply (AC) V/Hz 230~(+/- 10%)/50-60 Total electric power 2200 Heating element power 2000 Dimensions (W x H x D) 385x780x416 inch 15.2x30.7x16.4 Weight 57.3 Display LCD graphic touch-screen UK – I – E – F – RUS - CN...
  • Page 57 Velp Scientifica – UDK139 Operating Manual ANALYTICAL METHODS Standard methods N° 10 Each method includes the following parameters: Reference to official methods O addition from 0 to 200 ml NaOH addition from 0 to 150 ml from 00’.00” to 99’:59”...

  • Page 58: Wiring Diagram

    Velp Scientifica – UDK139 Operating Manual Wiring diagram 10004762/B5...
  • Page 59 Velp Scientifica – UDK139 Operating Manual N° Descrizione Fuse 6.3x32 15A ON/OFF switch with led Operatingl thermostat Safety thermostat Steam generator Door open trip switch Steam generator Steam electrovalve Discharge electrovalve Boiler outlet electrovalve Distillation residues discharge electrovalve Water inlet electrovalve...

  • Page 60: Hydraulic Scheme

    Velp Scientifica – UDK139 Operating Manual Hydraulic scheme 10004762/B5...
  • Page 61 Velp Scientifica – UDK139 Operating Manual EPDM = Butyl MQ/MVQ = Silicone PTFE = Teflon LLDPE = Low density polyethylene 10004762/B5...

  • Page 62: Warranty

    VELP Scientifica. In accordance with this guarantee VELP SCIENTIFICA undertakes to repair any units resulting as faulty due to the quality of the materials used or poor workmanship.

  • Page 63: General Description Of Kjeldahl's Method For The Measurement Of Organic Nitrogen

    For practical safety reasons for operators and the environment these prescriptions were modified. In following paragraphs, the general lines of present Kjeldahl method with the use of a high steam generation capacity apparatus as the model VELP UDK 139 are described. Sample range...

  • Page 64: B5 3

    Velp Scientifica – UDK139 Operating Manual Selenium dioxide (SeO ) and 100 g of anhydrous Sodium sulphate (Na ) are dissolved by 500 ml of ammonia free water and then 500 ml of concentrated sulphuric acid are added. Ammonia free distilled water for dilutions Add 0.1 ml of concentrated sulphuric acid (H...
  • Page 65 Velp Scientifica – UDK139 Operating Manual Catalysts Mercury is considered the best catalyst for Kjeldahl oxidative digestion, but its toxicity for man and the environment brought to dismiss its use. The same can be said for • 5 H Selenium. To-day Copper sulphate (CuSO O) with lower environmental damage is commonly used.
  • Page 66 Velp Scientifica – UDK139 Operating Manual Steam distilled ammonia can be collected with the condensate from the water cooled condenser in two different ways: a) in a classical solution of sulphuric acid of known titre and following back-titration. b) more recently, by a solution 4% of boric acid (H ).
  • Page 67 Velp Scientifica – UDK139 Operating Manual Definitions Total Kjeldahl nitrogen (TKN) is defined as the sum of ammonia nitrogen and organic nitrogen converted to ammonium sulphate in the mineralization conditions adopted by the method. Organic Kjeldahl nitrogen is given by the difference between the value of total Kjeldahl nitrogen and the value of ammonia nitrogen.

  • Page 68: Aoac, Method 960.52, Microchemical Determination Of Nitrogen-Micro-Kjeldahl Method

    Velp Scientifica – UDK139 Operating Manual AOAC, method 960.52, Microchemical determination nitrogen- Micro-Kjeldahl method AOAC International 1990. Official Methods of Analysis of AOAC International , 15 ed., The Association , Arlington, VA. This method ISN’T suitable for sample materials having N-N or N-O bonds.
  • Page 69 Velp Scientifica – UDK139 Operating Manual 2) Reagents for digestion: for each sample add in the test tube:  1 catalyst tablets ST (code CT0006609) (containing Selenium as catalyst)  2.0ml of sulphuric acid concentrated, 96-98% Normally, the sample weight to analyse is 15mg about; add 0.1ml of acid more for every 10mg of dried organic substance >15mg.

  • Page 70: Analytical Procedure Typical Analytical Scheme For Organic Nitrogen

    Place the digestion tube in the digestion unit: i.e. DK6 or DK20 Digest the samples Cool the digestion tubes Place a digestion tube with sample in UDK 139 unit Start the programmed automatic distillation cycle Titrate distillate Compute the results...

  • Page 71: Analytical Methods

    Velp Scientifica – UDK139 Operating Manual Analytical Methods 1 - Kjeldahl method to determine the protein content on milk and derived products The protein content of raw cow milk is meanly 3,2 g/100 ml (512 mg of nitrogen). Human milk is poorer in proteins (1 g/100 ml), while the milk of other animals is richer than cow milk (sheep 5,6 g/100 ml).

  • Page 72: Kjeldahl Method To Determine The Protein Content On Almonds, Nuts, Hazelnuts

    Velp Scientifica – UDK139 Operating Manual 2 - Kjeldahl method to determine the protein content on almonds, nuts, hazelnuts Procedure 1 Sample: grind the sample by a suitable device. Weigh 0.5-0.8 g of sample with an accuracy of  0.1mg.

  • Page 73: Kjeldahl Method To Determine The Protein Content On Coconuts

    Velp Scientifica – UDK139 Operating Manual 3 - Kjeldahl method to determine the protein content on coconuts Procedure 1 Sample: grind the sample by a suitable device. Weigh 0.5-0.8g of sample with an accuracy of 0.1mg. 2 Reagents for digestion: for each sample add in the test tube:...

  • Page 74: Kjeldahl Method To Determine The Protein Content On Peanuts And Brazil Nuts

    Velp Scientifica – UDK139 Operating Manual 4 - Kjeldahl method to determine the protein content on peanuts and Brazil nuts Procedure 1 Sample: grind the sample by a suitable device. Weigh 0.5-0.8g of sample with an accuracy of 0.1mg. 2 Reagents for digestion: for each sample add in the test tube:...

  • Page 75: Kjeldahl Method To Determine The Protein Content On Beer

    Velp Scientifica – UDK139 Operating Manual 5 - Kjeldahl method to determine the protein content on beer Among components of soluble extract of beer there are proteins and aminoacids. Soluble extractives represent from 3% to 12% of the weight of beer.

  • Page 76: Kjeldahl Method To Determine The Protein Content On Barley Malt

    Velp Scientifica – UDK139 Operating Manual 6 – Kjeldahl method to determine the protein content on barley malt Procedure 1) Sample: 1 g of malt finely grinded and sieved to 2 mm, previously dried in oven at 105°C up to constant weight, accurately weighed and transferred quantitatively in a test tube.

  • Page 77: Kjeldahl Method To Determine The Protein Content On Cereals And Feed

    Velp Scientifica – UDK139 Operating Manual 7 - Kjeldahl method to determine the protein content on animal feed Procedure 1) Sample: 2 g about of grinded product, sieved to 2 mm and dried at 105 °C up to constant weight, accurately weighed and transferred quantitatively in a test tube.

  • Page 78: Kjeldahl Method To Determine The Protein Content On Wheat

    Velp Scientifica – UDK139 Operating Manual 8 - Kjeldahl method to determine the protein content on wheat Procedure 1) Sample: grind the sample by a suitable device. If the result is to be expressed on dried sample, perform a separate determination of the humidity on the ground sample.

  • Page 79: Kjeldahl Method To Determine The Protein Content On Oats, Barley, Corn, Rice, Rye

    Velp Scientifica – UDK139 Operating Manual 9 - Kjeldahl method to determine the protein content on oats, barley, corn, rice, rye Procedure 1) Sample: grind the sample by a suitable device. If the result is to be expressed on dried sample, perform a separate determination of the humidity on ground sample.

  • Page 80: Kjeldahl Method To Determine The Protein Content On Soya Beans And Lupins

    Velp Scientifica – UDK139 Operating Manual 10 - Kjeldahl method to determine the protein content on soya beans and lupins Procedure 1) Sample: grind the sample by a suitable device. If the result is to be expressed on dried sample, perform a separate determination of the humidity on ground sample.

  • Page 81: Kjeldahl Method To Determine The Protein Content On Canned Cat/Dog Food

    Velp Scientifica – UDK139 Operating Manual 11 - Kjeldahl method to determine the protein content on canned cat/dog food Procedure 1) Sample: homogenize the sample by a suitable device. For samples having a humidity content up to 60%, weigh 2g of sample with an accuracy of 0.1mg, for samples having a humidity content higher than 60% weigh 3g of sample with the same accuracy.

  • Page 82: Kjeldahl Method To Determine The Protein Content On Forage And Straw

    Velp Scientifica – UDK139 Operating Manual 12 - Kjeldahl method to determine the protein content on forage and straw Procedure 1) Sample: cut the sample by a pair of scissors to a length of 2-3 cm about. Dry the sample and finally grind by a suitable device. Weigh 1g of sample with an accuracy of ...

  • Page 83: Kjeldahl Method To Determine The Protein Content On Bacon, Ham, Hot Dog, Salami, Sausage

    Velp Scientifica – UDK139 Operating Manual 13 - Kjeldahl method to determine the protein content on bacon, ham, hot dog, salami, sausage Procedure 1) Sample: 2g of sample weighed with an accuracy of 0.1mg after homogenizing. 2) Reagents for digestion: for every sample add in the test tube:...

  • Page 84: Kjeldahl Method To Determine The Protein Content On Meat And Derived Products

    Velp Scientifica – UDK139 Operating Manual 14 - Kjeldahl method to determine the protein content on meat and derived products The protein content in fresh bovine meat is about 20% (3% of proteic nitrogen about). Dried salted meats contain about 35% proteins, while salted meat show values between11 and 17%, depending on fat and water content.

  • Page 85: Kjeldahl Method To Determine The Protein Content On Bread And Baked Products

    Velp Scientifica – UDK139 Operating Manual 15 - Kjeldahl method to determine the protein content on bread and baked products Procedure 1) Sample: grind the sample by a suitable device. Weigh 2g of dried sample with an accuracy of 0.1mg.

  • Page 86: Kjeldahl Method To Determine The Protein Content On Compressed And Granular Yeast

    Velp Scientifica – UDK139 Operating Manual 16 - Kjeldahl method to determine the protein content on compressed and granular yeast Procedure 1) Sample: grind, if necessary, and make the sample homogeneous by suitable devices; weigh 0.5-0.7 g of sample with an accuracy 0.1mg.

  • Page 87: Kjeldahl Method To Determine The Protein Content On Liver Patè

    Velp Scientifica – UDK139 Operating Manual 17 - Kjeldahl method to determine the protein content on liver patè Procedure 1) Sample: 2g of sample weighed with an accuracy of 0.1mg after homogenizing by suitable device. 2) Reagents for digestion: for each sample add in the test tube:...

  • Page 88: Kjeldahl Method To Determine The Protein Content On Sugar, Syrup, Molasses

    Velp Scientifica – UDK139 Operating Manual 18 - Kjeldahl method to determine the protein content on sugar, syrup, molasses Procedure 1) Sample: weigh 1g of sample with an accuracy of  0.1mg (2g for molasses with the same accuracy). 2) Reagents for digestion: for each sample add in the test tube:...

  • Page 89: Kjeldahl Method To Determine The Protein Content On Wheat Spaghetti And Macaroni, Egg Pasta

    Velp Scientifica – UDK139 Operating Manual 19 - Kjeldahl method to determine the protein content on wheat spaghetti and macaroni, egg pasta Procedure 1) Sample: break the pasta in small pieces by hands or suitable device and mix well. Grind finally the sample by a suitable device. Weigh 1g of sample with an accuracy of 0.1mg.

  • Page 90: Kjeldahl Method To Determine The Protein Content On Grain Spaghetti, Macaroni

    Velp Scientifica – UDK139 Operating Manual 20 - Kjeldahl method to determine the protein content on grain spaghetti, macaroni Procedure 1) Sample: break the pasta in small pieces by hands or suitable device and mix well. Grind finally the sample by suitable device. Weigh 1g of sample with an accuracy of ...

  • Page 91: Kjeldahl Method To Determine The Protein Content On Plants (Vegetable)

    Velp Scientifica – UDK139 Operating Manual 21 - Kjeldahl method to determine the protein content on plants (vegetable) Procedure 1) Sample: mince and homogenize the sample by suitable devices, then weigh 0.5- 1.5 g in the test tube. 2) Reagents for digestion: for each sample add in the test tube:...

  • Page 92: Kjeldahl Method To Determine The Protein Content On Mushrooms

    Velp Scientifica – UDK139 Operating Manual 22 - Kjeldahl method to determine the protein content on mushrooms The average protein content on fresh mushrooms is 2-4%. Procedure 1) Sample: 10g of ground dried sample. 2) Reagents for digestion: for each sample add in the test tube:...

  • Page 93: Kjeldahl Method To Determine Total Nitrogen On Crude Oil And Fuels (Iso N. 333)

    Velp Scientifica – UDK139 Operating Manual 19.2 Pre-defined Methods for different samples 23 - Kjeldahl method to determine total nitrogen on crude oil and fuels (ISO n. 333) Procedure 1) Sample: homogenize the sample by shaking before analysis. Weigh 1g of sample with an accuracy of ...

  • Page 94: Kjeldahl Method To Determine Total Nitrogen On Abs, San, Rubber

    Velp Scientifica – UDK139 Operating Manual 24 - Kjeldahl method to determine total nitrogen on ABS, SAN, rubber Procedure 1) Sample: RUBBER: the sample is cut in small pieces and then ground. 0,5 g of sample accurately weighed are used for the analysis.

  • Page 95: Kjeldahl Method To Determine Total Nitrogen In Urea

    Velp Scientifica – UDK139 Operating Manual 25 - Kjeldahl method to determine total nitrogen in urea The method is suitable for the determination of urea content in aminoplastics, i.e. urea-formaldehyde resins. Procedure 1) Sample: the sample is ground in order to obtain a powder very fine and homogeneous .

  • Page 96: Kjeldahl Method To Determine Total Nitrogen On Water

    Velp Scientifica – UDK139 Operating Manual 26 - Kjeldahl method to determine total nitrogen on water The value obtained by this method corresponds to the sum of organic nitrogen (proteins, nucleic acids, urea, synthetic organic chemicals) and ammonia nitrogen. The measurement of this parameter is required by Italian laws 319/76 and 650/79 for the discharge of wastewaters in lakes, direct or indirect, included in a band of 10 km from the coast line (organic + ammonia + nitrous + nitric = 10 mg N/l maximum).

  • Page 97: Kjeldahl Method To Determine Total Nitrogen On Soil

    Velp Scientifica – UDK139 Operating Manual 27 - Kjeldahl method to determine total nitrogen on soil A soil of good fertility contains 2-3% of organic matter mainly humus which is composed by 4 - 6% of nitrogen. There is also some ammonia nitrogen (some ppm) which is to be determined separately and substracted from the value of Kjeldahl’s nitrogen obtained,if organic...

  • Page 98: Kjeldahl Method To Determine Gelatin On Paper

    Velp Scientifica – UDK139 Operating Manual 28 - Kjeldahl method to determine gelatin on paper During paper manufacture animal glue or gelatin, casein and soya proteins are used as bonding agents. Kjeldahl’s method gives reliable results for the protein content if other nitrogen compounds are not present (e.g.

  • Page 99: Kjeldahl Method To Determine Casein On Paper

    Velp Scientifica – UDK139 Operating Manual 29 - Kjeldahl method to determine casein on paper During paper manufacture animal glue or gelatin, casein and soya proteins are used as bonding agents. Kjeldahl’s method provides reliable results for the protein content if are not present other nitrogen compounds (e.g.

  • Page 100: Kjeldahl Method To Determine Total Nitrogen On Sludges From Wastewater Treatment Plants

    Velp Scientifica – UDK139 Operating Manual 30 - Kjeldahl method to determine total nitrogen on sludges from wastewater treatment plants The final use of sludges from municipal wastewater treatment plants should be on agricultural land for the recovery of useful nutrients. This is suggested also by the...

  • Page 101: Method To Determine The Alcohol Strength On Wines, Musts And Spirits By Steam Distillation And Volume

    - 1 l test tube (code A00001083) - 200 ml graduated flasks with stopper - Pycnometer (volume 100 ml or 50 ml) - Cooled Incubator (VELP Scientifica FOC Series) - Analytical balance 2a) Procedure for wine To remove the carbon dioxide, stir gently the sample (250-300 ml in a 1000 ml flask) with a VELP magnetic stirrer.
  • Page 102 Velp Scientifica – UDK139 Operating Manual Collect the distillate in the 200 ml graduated flask used to measure the wine quantity. *set a distillation time to obtain a maximum of 200 ml of distillate. After the distillation, position the receiving flask in the thermostat for about 15 min. and finally bring up to volume (200 ml) using distilled water at 20 °C.

  • Page 103: Method To Determine The Residual Urease Activity In Soya Beans

    Velp Scientifica – UDK139 Operating Manual 32 - Method to determine the residual urease activity in soya beans To evaluate if a soya bean sample, submitted to thermal treatment (toasting), has been treated in a correct way, it is possibile to measure the residual activity of the enzyme urease.

  • Page 104: Method To Determine Urea Nitrogen In Feed And Roughages

    Velp Scientifica – UDK139 Operating Manual 33 - Method to determine urea nitrogen in feed and roughages During ensiling of green forages some urea can be added. Some feed can be supplemented with urea in order to increase raw protein content. Urea content can be determined separately from other nitrogen compounds by the enzyme urease which hydrolizes urea to ammonia and carbon dioxide.

  • Page 105: Determination Of The Volatile Acidity Of Tomato Paste

    Velp Scientifica – UDK139 Operating Manual 34 - Determination of the volatile acidity of tomato paste The volatile acids are measured ,in the presence of phenolphthalein indicator, in the distillate obtained by steam distillation of a proper amount of sample.
  • Page 106 Velp Scientifica – UDK139 Operating Manual Distillation time = 5 minutes Steam = 100% Push START to initiate the cycle Collect 150ml of distillate. To avoid damage to the distillator it is strongly recommended NOT to use the “removal of the distillation residues” function.

  • Page 107: Method To Determine The Volatile Acidity Of Wines

    Velp Scientifica – UDK139 Operating Manual 35 - Method to determine the volatile acidity of wines The volatile acidity is due to the acids belonging to the acetic series which are present in the wines as free or salt forms.
  • Page 108 Velp Scientifica – UDK139 Operating Manual 3) Titration: titrate using the solution 0.1M of sodium hydroxide in presence of 2 drops of phenolpthalein solution, being n the volume in ml used. Add 4 drops of diluted hydrochloric acid 1/4 , 2ml of starch-water, and some crystals of potassium iodide (in order to make more visible the colour change).
  • Page 109 Velp Scientifica – UDK139 Operating Manual of sodium thio-sulphate and 1ml of solution of ammonic ferric sulphate. If salycilic acid is present a violet colour will appear. -dosage of the salycilic acid: In the flask described above mark the level of the distillate volume. Empty the flask and wash it.

  • Page 110: Kjeldahl's Method To Determine Total Nitrogen In Crude Oil, Lubricants And Fuel Oils (Astm, D3228-96)

    Velp Scientifica – UDK139 Operating Manual 36 - Kjeldahl’s method to determine total nitrogen in crude oil, lubricants and fuel oils (ASTM, D3228-96) Combined nitrogen in petrochemical fuels gives origin by combustion to nitrogen oxides whose emission in the atmosphere is subjected to limitations.
  • Page 111 Velp Scientifica – UDK139 Operating Manual 4) Distillation and titration Place in position the test tube with digested sample in the unit UDK 139 Set the following analytical parameters: Factor: 0.00 Addition of reagents: H2O: 70 ml : :30 ml...

  • Page 112: Method To Determine Nitric Nitrogen On Water After Reduction To Ammonia Nitrogen (Devarda's Alloy Method)

    2) Reagent for the reduction of nitrates (and nitrites) to ammonia for each sample: 2 g Devarda’s alloy powder 3) Reduction and distillation/titration: introduce Devarda’s alloy in the tube and place it in the unit UDK 139. Set the following analytical parameters: Reagents addition: O = 0 ml...

  • Page 113: Method To Separate Ammonia In Water From Interfering Substances

    Velp Scientifica – UDK139 Operating Manual 38 - Method to separate ammonia in water from interfering substances Ammonia nitrogen is an important parameter for the management of a water treatment plant. Its direct determination in turbid waters, coloured or rich in magnesium, ammines and other organic substances is subjected to large errors.

  • Page 114: Determination Of Phenols In Drinking Water And In Industrial Wastes

    Velp Scientifica – UDK139 Operating Manual 39 - Determination of phenols in drinking water and in industrial wastes The determination of phenols is one of the routine analysis in order to assess the quality in drinking and ground water and in domestic and industrial wastes.
  • Page 115 Velp Scientifica – UDK139 Operating Manual Steam power: 50 % Position the test tube containing 10 ml of sample into the distillation unit UDK and start the distillation. Push START to begin the distillation. About 200 ml of distillate are collected into a 500 ml volumetric flask.

  • Page 116: Separation Of Hydrocyanic Acid From Wastewaters

    Velp Scientifica – UDK139 Operating Manual 40 - Separation of hydrocyanic acid from wastewaters Heavy metal complexes, sulphides, aromatic amines, oxidants and dyes interfere with colorimetric or titrimetric determination of cyanides. In these cases hydrocyanic acid is to be separated from water sample by a distillation. Steam distillation at 95- 100°C gives results 0,5-1% lower than exact value, due to HCN hydrolysis to...
  • Page 117 Velp Scientifica – UDK139 Operating Manual Begin the distillation by START. 100-120 ml of condensate are collected and the flask content can be adjusted to the volume with the washings in a volumetric flask 200 ml (the same volume of the sample).

  • Page 118: Method To Control The Efficiency Of An Anaerobic Digester By Determination Of Volatile Acids Content In Digesting Sludge

    Velp Scientifica – UDK139 Operating Manual 41 - Method to control the efficiency of an anaerobic digester by determination of volatile acids content in digesting sludge The volatile acids content in a slurry submitted to anaerobic digestion is considered the best index of process performance when compared to alkalinity level.
  • Page 119 Velp Scientifica – UDK139 Operating Manual 4) Titration: after the addition of phenolphthalein indicator (10 drops) titrate by sodium hydroxide 0,04 N, until pink colour persists. 5) Computation: the result is obtained by the formula: mg/l volatile acids (as acetic acid) =...

  • Page 120: Determination Of Ammonia Nitrogen In Organic Fertilizers According To The Kjeldahl Method

    Velp Scientifica – UDK139 Operating Manual 42 - Determination of ammonia nitrogen in organic fertilizers according to the Kjeldahl method Procedure 1) Sample: the sample must be ground in order to obtain an homogeneous powder (particles dimension 1mm). 0.7-3.5g of sample are then accurately weighed (with a precision of 0.1 mg) and quantitatively transferred in a test tube.

  • Page 121: Determination Of The Total Volatile Basic Nitrogen (Tvbn) In Fresh And Frozen Fish

    Velp Scientifica – UDK139 Operating Manual 43 - Determination of the total volatile basic nitrogen (TVBN) in fresh and frozen fish The controls required by EEC aimed at preventing fish and seafood not suitable for human consumption from being put on the market, can include some chemical controls, one of them being the TVBN determination.

  • Page 122: Declaration Of Conformity

    Declaration of conformity We the manufacturer VELP SCIENTIFICA s.r.l. Address Via Stazione, 16 20865 USMATE (MB) Italy under our responsibility declare that the product is manufactured in conformity with the following standards: EN 61010-1/2001 EN 61010-2-010/2003 EN 61010-2-081/2003 EN 61326-1/2006...
  • Page 123 Velp Scientifica – UDK139 Operating Manual Thank you for having chosen a VELP product ! Since 1983 Velp has offered to professionals in the sector a range of sophisticated and reliable equipment with excellent operating capacity and backed by high levels of know-how at competitive prices.

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