Multiwave GO Plus Instrument Software Notes

Safety Instructions

Pay close attention to safety instructions and warnings in the manual and on the product.

• Do not start using the instrument before reading and understanding the safety instructions.
• Read the manual before using Multiwave GO Plus, following all hints and instructions.
• Keep the manual with the instrument and transfer it to other persons.
• The manual doesn't address all safety issues; establish health and safety practices and determine regulatory limitations.
• Anton Paar GmbH only warrants proper functioning if no modifications are made to mechanics, electronics, and firmware.
• Only use Multiwave GO Plus for its described purpose.
• Instruct personnel in the operation and maintenance of Multiwave GO Plus.
• Ensure operators are trained in correct and safe use.
• Operators must be able to judge dangerous situations and prevent accidents and damage.
• Operators must have knowledge of chemistry and its rules.
• Move or lift Multiwave GO Plus with assistance, ensuring it's free of chemicals.
• Lift the instrument without the rotor or pack the rotor as described in section 13.1
• Only transport Multiwave GO Plus horizontally.
• Never lift Multiwave GO Plus by the lid.
• Follow installation instructions (section 5) by qualified personnel.
• Multiwave GO Plus is not explosion-proof and must not be operated in areas with explosion risk.
• Use the instrument in a corrosive-free atmosphere.
• Allow Multiwave GO Plus to acclimatize to ambient temperature before switching it on.
• Only use sensors, accessories, consumables, or wearing parts supplied by Anton Paar GmbH.
• Do not operate the instrument under conditions that could result in damage to property, injuries, or loss of life.
• Supervise Multiwave GO Plus during operation.
• In case of damage or malfunction, do not continue operating Multiwave GO Plus.
• Do not operate Multiwave GO Plus if a fault is suspected.
• Do not store containers with flammable reagents or ignitable materials close to or on the instrument.

Installation of exhaust hose

The exhaust hose safely removes acid vapors from the instrument to the exhaust system. A loosened exhaust hose could release toxic substances or splinters. Secure the exhaust hose with the supplied hose clip to the flange of the exhaust of Multiwave GO Plus and fix the open end of the exhaust hose with the delivered clip in the fume hood.

• Multiwave GO Plus has to be connected to a fume hood with a minimum exhaust capacity of $100 m^3/h$. It is the owner's responsibility to ensure the exhaust system is working properly.
• Install the exhaust hose by guiding it first downwards and then going upwards again (U-shape) to avoid reflux of condensed acids to the instrument's electronics.
• Proper cleaning and maintenance are vital for the instrument's service life.
• Perform maintenance and cleaning routines regularly.
• Switch off the instrument and disconnect the mains plug before cleaning.
• During cleaning and maintenance, you might contact hazardous chemicals. Always wear goggles, protective gloves, and appropriate protective clothing.
• Do not open the instrument casing, as this would uncover live parts. Service procedures must be carried out by authorized personnel or by Anton Paar GmbH.
• Installation, service and repair procedures will only be carried out if the "Safety Declaration for Instrument Repairs" form has been filled out and passed on to the Anton Paar service engineer.
• In case of an instrument damage do not continue to operate the instrument. Call an authorized Anton Paar service engineer.
• Observe the legal requirements in your country concerning the disposal of Multiwave GO Plus.
• In case of a sudden pressure build-up inside the cavity (vessel breakage), the lid may slightly open for less than a second and release noxious reaction gases and/or parts.
• Do not lean against the instrument.
• Keep a safe distance of approximately $1 m$ from Multiwave GO Plus during operation, especially when handling mixtures containing hydrofluoric acid.
• Observe the load limits given in section 8.
• The instrument lid can open, and parts can fall out with damaged closure parts. In case of a vessel breakage, the instrument must be checked by Anton Paar. Parts of the closure system may be damaged and have to be replaced
• If you abort a program, wait until the safety cooling has been automatically stopped.
• Do not operate Multiwave GO Plus if the lid does not stay in position due to possible gradual wear of the gas springs of the lid. Contact your Anton Paar representative.
• In case of a sudden pressure build-up inside the instrument, the lid could be damaged. Always check the lid for intactness prior to operation. Ensure that there is no deformation, no formation of gaps. In case of any (mechanical) modification of the lid microwave radiation can leak.
• Foreign parts inside the microwave cavity may lead microwave radiation to the outside of the instrument. Never place any parts (e.g., spatula) into the microwave cavity and remove damp cloths for cleaning immediately after use.
• During operation (microwave energy "ON"), an electromagnetic field is generated by two transformers that can provoke the heart or central nervous system and can destroy data storage medium, electronic or mechanical components. People with pacemakers should keep a distance of at least $50 cm$ and during operation $1 m$ to the instrument to ensure maximum safety. Keep credit cards or other cards with a magnetic read-write band away from Multiwave GO Plus.
• Multiwave GO Plus must only be connected to an approved standard socket with protective conductor.
• Make sure that the local mains supply and frequency correspond to the values on the type plate of the instrument (AC $230 V ±10 \%$, 50/60 Hz).
• Only use an outlet with protective earth to avoid the risk of an electric shock and use the cables supplied by Anton Paar GmbH.
• The mains plug has to be freely accessible and on the outside of the fume hood, so that you can immediately disconnect the plug in the case of an emergency.
• Only use the supplied mains cable, which is designed for the high power input of the instrument.
• Operating the instrument in a humid and/or corrosive atmosphere can result in an electric shock. Ensure that the installation conditions are fully met.
• In case that liquid accidentally enters the instrument, immediately switch off the instrument and disconnect the mains supply. If corrosive liquid has entered the instrument, call an authorized Anton Paar service engineer. Do not continue to use the instrument.
• Exothermal reactions may result in an uncontrollable pressure increase which can lead to a vessel breakage.
• Start with a small initial weight for unknown samples and increase the initial weight only, if it is ensured that the sample is not highly reactive (temperature gradient, venting intensity).
• Close the screw cap of the pressure vessel properly as shown in fig. 24.
• Always chop up metal chips and fully cover them with reagent.
• Observe the restrictions on use given in appendix A.
• During experiments with Multiwave GO Plus popping, whistling and hissing could be heard.
• In case of an (unlikely) vessel breakage noxious reaction gases will be released.
• In case of a vessel breakage leave the room and wait until the exhausting process has finished. Afterwards open the window(s) to vent the room. Carefully clean the instrument. During cleaning wear personal protective equipment (safety goggles, protective gloves and appropriate protective clothing).
• After breakage of the vessel do not continue to operate the instrument. Call an authorized Anton Paar service engineer.
• In case of an instrument damage do not continue to operate the instrument. Call an authorized Anton Paar service engineer.
• In case of a power failure or measurement failure the vessels inside the cavity will not be cooled down.
• Observe and adhere to your national safety regulations for handling the chemicals (e.g. use of safety goggles, protective gloves, respiratory protection).
• During handling the vessels and instrument on routine basis you might get into contact with hazardous chemicals, depending on your performed applications. Always wear personal protective equipment (safety goggles, protective gloves and appropriate protective clothing).
• During normal operation, acidic condensate may accumulate inside the exhaust hose. Use personal protective equipment when handling or cleaning the exhaust hose.
• In case of a power failure or interrupted air flow (Error message: "Not available fan speed sensor") a dangerous concentration of acid and/or solvent vapors might be released.
• In case of a power failure or interrupted air flow (Error message: "Sensor is not available or connected") a dangerous concentration of acid and/or solvent vapors might be released.

Warning Signs

The symbols on Rotor 12HVT50 of Multiwave GO Plus call attention to the fact, that the screw cap must be closed without overlap at the vent hole and in case of malfunction the rotor can be hot, although cooling has finished and the lid lock has been released.

• Read the instruction manual before using the instrument.
• Tighten the screw cap with the handling tool (see fig. 24) until the spring holder and the spring holder insert are on the same level (see fig. 25).
• Do not touch the rotor without adequate protective measures.
• Always wear personal protective equipment (safety goggles, protective gloves and appropriate protective clothing).

This symbol on the calibration unit of Multiwave GO Plus calls attention to the fact, that the calibration unit can be hot.

• Read the instruction manual before using the calibration unit.
• Do not touch the calibration unit without adequate protective measures.
• Do not touch the white ceramic heating element of the calibration unit.

Multiwave GO Plus - an Overview

Multiwave GO Plus is a microwave digestion system, optimized for economic routine analysis of environmental samples, food quality control, plant material and other material. A single magnetron delivers up to $1000 W$ microwave power over the full power range. The software prevents thermal overshoots, and the microwave applicator design provides utmost field density, allowing efficient and uniform heating across all vessel positions. The exhaust unit continuously removes reaction heat and gases to extend the durability of the materials used.

The sensor system of Multiwave GO Plus enables automatic detection of each pressure vessel, as well as monitoring of the rotor revolution, to ensure uniform microwave heating and prevent localized overheating.

For precise reaction control, the vessel temperature is continuously monitored with an IR temperature sensor, measuring from the bottom of the cavity. A robust temperature model calculates and displays the inner temperature of the pressure vessels. To control the temperature and protect against overheating, the magnetron is equipped with a temperature sensor, which shuts down the magnetron immediately in case of overheating.

Multiwave GO Plus automatically detects extreme acid venting. A warning sign appears with detailed information at the end of the run.

Functional Components

• Display
• Lid opener
• USB port
• Mains switch
• Port mains cable
• Fan
• Calibration port
• USB port
• Exhaust flange

Rotors and Vessels

High-throughput rotor with 12 high-performance pressure-activated-venting vessels made of PTFE-TFM (50 mL) for routine and quality control applications.

• Rotor lid magnet
• Rotor lid
• Pressure vessel HVT50
• Rotor body
• Centering plate
• Handle

Rotor 12HTV50

• Weight: $5 kg$ (incl. 12 pressure vessels)
• Applicable vessel: Pressure vessel HVT50
• No. of vessels: 12

Pressure Vessel HVT50

High-performance pressure vessel with pressure-activated venting for routine and quality control applications made of PTFE-TFM.

Calibration Unit

The calibration unit is required to calibrate the IR temperature sensor.

Checking the Supplied Parts

Multiwave GO Plus was tested and packed carefully before shipment. However, damage may occur during transport.

• Keep the packaging material (box, foam piece, transport protection) for possible returns and further questions from the transport and insurance company.
• There are many small parts distributed throughout the packaging - please retain all packaging materials until installation is complete and all parts are accounted for.
• Check the delivery for completeness by comparing the supplied parts to those noted in the table below.
• If a part is missing, contact your Anton Paar representative.
• If a part is damaged, contact the transport company and your Anton Paar representative.

Installation

When installing Multiwave GO Plus, the following requirements have to be met:

• Installation in a non-corrosive environment
• Installation in areas without risk of explosion
• An approved standard socket with protective conductor (TN-C or TN-C-S).
• A fume hood with a minimum exhaust capacity of $100 m^3/h$

To ensure trouble-free processing:

• Never place Multiwave GO Plus:
  • next to a heating facility, like a water bath, sand bath or a hot plate.
  • near an air conditioning, ventilation system or an open window.
  • in direct sunlight.
• Keep the instrument away from magnetic fields.
• Avoid vibrations.
• The surrounding environment of the instrument must be kept clean.
• A distance of additionally $15 cm$ on all sides is required to ensure proper venting of Multiwave GO Plus.
• The instrument has to be easily accessible for operation.
• Any spills of chemicals, solvents etc. have to be removed immediately using appropriate equipment (see also section 11).
• The valid Laboratory Safety Regulations and Occupational Safety Regulations must be observed.

Operating Multiwave GO Plus

Multiwave GO Plus can be operated by:

• Tapping the elements on the touchscreen (see section 6.2).
• Using a USB mouse and clicking on the elements on the touchscreen.
• Using an external keyboard for entering characters.

Elements of the Start Screen

The following symbols are shown in the global status area. Tap the button to open the diagnosis window, which displays the current instrument- or run status.

Elements of the Run Screen

After starting a run, the run screen appears, and Multiwave GO Plus starts processing the loaded samples.

A factory-set Multiwave GO Plus is freely accessible without password and the administrator is automatically logged on. If user accounts are created and passwords set, you have to pass a logon procedure.

Setting-up the Instrument

Target Cooling Temperature

Choose a value between $40 °C$ and $70 °C$ to which the sample is cooled down at the end of the run.

Venting Warning

The administrator has the possibility to activate or deactivate the venting warning.

Regional Settings

Define the basic settings for data entry.

Data Memory Settings

Multiwave GO Plus can store up to 100 runs. After 100 runs you will be asked to delete stored runs, so that Multiwave GO Plus can be operated again.

System Security Settings

Security Level

You can set the security level to "Low" or "Advanced", to activate audit trail and user management according to 21 CRF part 11.

Logon Settings

Additionally to the predefined logon procedure you can define parameters which have to be adhered when creating a new password.

System Security Settings

Audit Trail

The audit trail function is part of the 21 CRF part 11, to be conform with the documentation requirements of manufactures in the pharmaceutical industry.

Increased Security

When activated, the following additional functions are activated:

• Lock user account after three failed logon attempts.
• Auto logon is not allowed.
• User name must have at least 6 characters.
• User name must be entered instead of selected from list.
• Last 5 passwords must not be used.
• Only exported data can be deleted.

Programming a Run

Multiwave GO Plus offers predefined methods, including all necessary settings, to perform a run.

New experiments are created directly from the start screen. The last, performed run is suggested by default.

You can create a new method in two ways:

• Modify a predefined method directly from the start screen and save it after processing as new method (refer to section 7.1.1).
• Create a new method in the "Methods" menu (refer to section 7.1.2).

Application

Multiwave GO Plus is applicable for acid digestion. The matrices of organic or inorganic samples are destroyed by using concentrated acids, bringing the analytes into solution, thus into a measurable form.

Commonly Used Acids

• Nitric acid, $HNO_3$ ($65 \%$)
• Hydrochloric acid, $HCl$ ($30 – 32 \%$)
• Hydrofluoric acid, $HF$ ($40 – 48 \%$)
• Boric acid, $H<em>3BO</em>3$ (cold-saturated solution, $5 – 5.5 \%$)
• Sulfuric acid, $H<em>2SO</em>4$ ($96 \%$) (limited in Multiwave GO Plus)
• Phosphoric acid, $H<em>3PO</em>4$ ($85 \%$) (limited in Multiwave GO Plus)

Restrictions

• If only $HCl$ is used as reagent, it is recommended to add at least a small amount of $HNO<em>3$. Pure $HCl$ absorbs microwave energy inefficiently, by adding $HNO</em>3$ the heating performance will be improved.
• Acid amounts between $3 mL$ and $15 mL$ are recommended for most of the samples.
• For a small number of vessels (1 or 3) use an acid amount of not less than $6 mL$ to provide enough mass for microwave absorption.
• Amount of organic solvents in a sample:
  • max. $10 \%$ (e.g. a sample which contains $40 \%$ solvent has to be diluted) AND
  • total content of organic solvents max.$1 g$
• $H<em>2SO</em>4$ and $H<em>3PO</em>4$ are mainly used as high-temperature oxidatives for difficult applications. $H<em>2SO</em>4$ can build insoluble sulfates, which may affect analytical measurements.
• $H<em>2SO</em>4$ and $H<em>3PO</em>4$ can be used in Multiwave GO Plus as part of an reagent mixture only, with a maximum content of $20 \%$ each.
• Ratio of sulfuric acid to nitric acid max. 1:4
• $H<em>2O</em>2$ has a high oxidation potential and can lead to vigorous reactions. The reagent mixture must not contain more than $6 \%$ of $H<em>2O</em>2$, and the amount of $H<em>2O</em>2$ is limited to $2 mL H<em>2O</em>2$ per vessel.

Special Case: HF

Hydrofluoric acid is particularly hazardous; therefore, additional precautions have to be taken. The risk of contamination with HF can be minimized by digestion runs at lower temperatures, without venting.

The matrices of organic or inorganic samples are destroyed by using concentrated acids, bringing the analytes into solution, thus into a measurable form. Acid digestion (total digestion) and acid leaching differ only in the completeness of the destruction of matrices.

• Prohibited:
  • Perchloric acid
  • Explosives
  • Undiluted organic solvents
  • Alkalines
• No explosives
• No flammable reagents
• No undiluted organic solvents
• Limitation of organic solvents in aqueous samples (max. of $10 \%$)
• Limitation of total content of organic solvents (max. of $1 g$ per vessel)

Portions for some sample types

Generic Methods

• ASTM D4309 (half-scale)
• ASTM E1645
• Cleaning
• EPA 3015A** (half-scale)
• EPA 3051A**
• EPA 3052
• Inorganic
• Organic A
• Organic B
• PQ***

restrictions with venting vessels

Setting the target temperature

• For HNO3, a target temperature not higher than $200 °C$ should be set, for pure HCl not higher than $185 °C$.
• With acid mixtures, the target temperature should be set considering the characteristics of the acid with the lowest boiling point.
• Take care – using Temperature Control Mode MIN or AVG may result in vessel temperatures above the target temperature. To avoid the venting of the acids the T-Limit should be set accordingly.

Setting the temperature limit

• Set the temperature limit according to table 4.

GeneralHints for samples

The best way to start digesting your samples is to select one of the generic methods. For safe and successful digestions consider the following hints and recommendations.

• Start with low sample weights ($100 – 200 mg$).
• Always use an increased ramp time (or use more than one ramp) for unknown or reactive samples.
• Choose the temperature control strategy depending on the samples: MIN or AVG control is recommended for inorganic/inert samples, while AVG or MAX control works best for organic/reactive samples.
• To ensure uniform temperature distribution during the run with the Multi Vessel Mode, the rotor has to be loaded symmetrically. Follow the load patterns in section 9.2.2.
• It is not recommended to digest samples with different acid mixtures in the same run. Due to the different microwave absorption and venting behavior of different acids the optimization of such run is very difficult.
• Different samples with similar reaction behavior can be safely digested in the same run. Do not form groups.
• If samples and blanks will be digested in the same run mix them alternating in the rotor.

Other materials

Organic Samples

• As a starting point method "Organic A" should be used.
• For the first digestion only small sample amounts between $100 – 200 mg$ should be used.
• The acid mixture should be selected depending on the elements to be measured as well as on the available analytical techniques.
• If a strong exothermic reaction takes place or if the method needs to be optimized for highest sample amounts, change from "Organic A" to "Organic B".
• Before using "Organic B" determine the temperature zone where exothermic reactions are triggered via using method "Organic A". That range can be recognized due to the obvious decrease of power besides constant or even increasing temperatures.
• If the trigger temperature is higher than $100 °C$, increase the first target temperature of the generic method “Organic B” accordingly.
• A target temperature of $180 °C$ is high enough for the digestion of a wide range of organic samples, while avoiding venting of the commonly used acid mixtures in the hold phase.
• Methods can be optimized for higher sample weight (increase of the ramp and hold time), as long as the restrictions in use for samples, acids and methods (see section 8.2, section 8.4, section 8.6) are taken into account.

Fat-rich Food Samples

Food samples that are rich in fat and proteins can be successfully digested with HVT50 vessels.

• Due to the fat content, the sample amount has to be limited to a maximum of $0.5 g$ for an acceptable digestion quality.
• A sample amount of $0.3 g$ can be digested with $5 mL$ of conc. HNO3 using the generic method Organic A.
• To increase the sample amount to a maximum of $0.5 g$, also increase the amount of HNO3 to $7 to 10 mL$.
• Observe the venting intensity and the weight losses during the process. If the losses are too high add 1-2 mL of water to the mixture to decrease the reactivity of $HNO_3$.

Alcoholic Beverages, Solutions with Organic Solvents

• Waste water with a sample volume of $25 mL$ can contain up to a maximum of 4 % solvent in order not to exceed the total limit of $1 g$.
• For spirits (like whiskey) with $50 \%$ alcohol, limit the sample weight to $2 g$ AND dilute with $8 mL$ of water to stay below the limit of $10 \%$ solvent.
• Wine ($15 \%$ alcohol) contains $1 g$ in $6.7 mL$ sample and needs $3.3 mL$ of water to reach the $10 \%$ limit. Even at the $10 \%$ concentration limit, alcohols may strongly react with $HNO_3$ even in the cold, let the mixture pre-react under the fume hood without closing the vessel. Let the mixture cool down before closing and performing the digestion.

Other solvents may require different target temperatures due to higher boiling points or less reactivity.

Polymer Samples

Polymers contain numerous additional functional components, like organic colors, inorganic pigments (silica, mica, TiO2 and more), stabilizers and softeners which make the digestion complex. Therefore, the respective polymers have to be tested individually. As starting point sample amounts between 0.1 - 0.3 g of polymers (without aromatic compounds or inorganic pigments) can be digested with $6 – 9 mL HNO_3$ and a target temperature of $190 °C$.

Petroleum Samples

The following samples from the petroleum industry can be tested with Multiwave GO Plus:

• In venting vessels it is recommended to use only $HNO_3$ to achieve the highest possible temperatures.
• Do not add $H<em>2O</em>2$, as it is not effective to regenerate $HNO_3$: with the first venting event most of the generated oxygen is lost.
• When the reaction is too strong (exothermal reactions, early and excessive venting or too high venting losses), dilute the nitric acid with 1-2 mL of water.
• Petroleum is carbon-rich and requires a higher amount of $HNO_3$ and also generates high volumes of reaction gases:
  • For $0.2-0.3 g$ sample use $5-6 mL$ of $HNO_3$.
  • For $0.5 g$ sample up to $10 mL$ of $HNO_3$ can be necessary.

Inorganic Samples

• For reactive samples such as ashes, oil contaminated sediments, sludges and soils the standard method EPA 3052 should be used. Depending on reactivity lower sample amounts, longer ramp times and customized acid mixtures are allowed.
• Total digestion, like in EPA 3052, allows residues and precipitation which can be filtered before analysis.
• Depending on samples and acid mixtures a run with up to fully loaded rotor can be carried out corresponding to the requirements of the standard methods.
• Inorganic samples such as sediments, sludges, soils and oils can be leached according to EPA 3051a using the method of the same name or method “Inorganic“.
• Reduce the ramp time for inorganic samples with no or insignificant organic content.
• Increase the ramp time for samples contaminated with organic compounds.