microwave digestion
TRANSCRIPT
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Microwave DigestionGamal A. Hamid
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Thanks
To everyone who has helped us with support,
new books, hard/soft ware
And over the internet. Special thanks for Milestone
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Basic theory
Microwave Types
Hardware
Safety
Software
Samples Preparations
Basic Rules
Applications
Contents
Basic Theory
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Microwaves Rays
Microwaves are a form of electromagnetic radiation with wavelengths ranging from one
meter to one millimeter; with frequencies between 300 MHz (100 cm) and 300 GHz (0.1 cm).
Microwaves are electromagnetic radiations with relatively low energy.
Microwaves promote the rotation of specific molecules in a reaction mixture. this rotation
results in increased molecular collisions and generation of heat.
The Polar reaction mixtures have the physical capability to interact with microwaves and
generate heat.
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Microwave Rays
c
H
λ= Wavelength
ε = wave height
C = Velocity
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Conductive Heating
• Heat passes through the vessel walls prior reaching
the reactants
• Slow and inefficient method dependent from
vessel material thermal conductivity
• Vessel temperature in excess of reaction mixture
temperature
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Microwave Heating
Liquids rapidly absorb microwave energy and Microwaves couple
with reaction mixture molecules
• Rapid temperature increase
• Independent from vessel material thermal conductivity
• Instantaneous localized superheating by ionic conduction
and dipole rotation
• No inertia (instant on-off)
• Dependant from ionic conduction and dipolar polarization
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Microwave Advantages
• Short digestion times. Minutes, not hours!
• No loss of volatile elements. Complete recovery of Hg,
As, Cd etc.
• No acid fumes. Improved laboratory working
conditions.
• No sample contamination from the environment.
• No cross contamination.
• Low blanks, as minimal quantities of acids are used.
• Unattended operation.
• Easily reproducible and fully documented methods.
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Microwaves Types
• Microwave Acid Digestion
• Microwave Extraction
• Microwave Synthesis
• Microwave Ashing
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Microwave Acid Digestion
Microwave digestion is widely recognized as
the most robust sample prep technique for AA,
ICP-OES, or ICP-MS analyses.
Microwave digestion involves combining the
sample matrix and acids in a pressurized
container and elevating the solution past the
boiling point of the acid which significantly
accelerates the digestion.
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Microwave Extraction
A solvent or combination is chosen to absorb
energy and heat quickly.
When performed in a closed-vessel, the power
is controlled to heat the solvents above their
boiling points and allow the extractions to be
performed much faster than older methods.
From a simple set-up of multiple vessels inside a
microwave cavity, the speed and productivity
enhancement has enabled a critical
advancement in sample preparation for the
organics field.
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Microwave Synthesis
• Chemical synthesis is the purposeful execution of
chemical reactions among opportune starting
materials (reagents) aimed to get a product or a
mixture of products (reaction mixture).
• Microwave instruments for synthesis have the
requirements of a very homogeneous microwave
field, a stirring device (normally magnetic) and
reliable sensors to measure operative variables
such as temperature, pressure and irradiated
power.
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Microwave Ashing
• The PYRO reduces ashing times, from hours to
minutes.
• allows the ashing of large quantities (50 grams and
up) of multiple samples.
• microwave ashing system can accommodate sample
crucibles made of different materials, such as
metals, quartz, porcelain etc.
• Just 30 seconds are enough for the Ultra FAST
crucible to go from 1000 degrees to room
temperature.
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Microwave Hardware
1. Magnetron
2. Rotating diffuser
3. Constraction
4. Sensors
5. Rotors MDR
6. Vessel
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1. Dual Magnetron
• Highest microwave power provides fast vessel heating
• The microwave is equipped with two magnetrons.
• Installed power is 1.800 watts allowing rapid heating of
even high throughput.
• Delivered microwave power: 1000W, controlled via
microprocessor in 10-Watt increments.
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Microwave Output Power Test
• A 1.0 litter container of water. Use a low, wide microwave
transparent container
• Place it in the rear of the cavity.
• The thermocouple should be removed and the jumper plug
installed.
• Stir the water and measure the initial temperature with an
accurate thermometer.
• Heat the water at maximum power for 60 seconds.
• Immediately after, stir the water and measure the maximum
final Temperature of the water.
Output power = (Tf - Ti) x 70
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2. Rotating Diffuser
Homogeneous microwave distribution
A pyramid-shaped rotating diffuser evenly
distributes the microwaves in the cavity.
This unique design ensures optimal microwave
distribution, preventing localized hot and
cold spots.
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3. Constraction
• Stainless steel door. Or impact-resistant glass window.
• Large illuminated microwave cavity
• Microwave cavity stainless steel housing with multilayer PTFE
plasma coating applied at over 350ºC.
• All hardware protected against acid/organic solvents with
polymer coating both inside and outside surfaces.
• Total of 7 micro switches of which 4 safety interlocks to prevent
microwave emission with open door.
• Exhaust located above the cavity separate from electronics to
prevent any corrosion.
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Pressure-Responsive Door
• The microwave door is based on the “moving wall”
principle used in high pressure autoclaves.
• The door is mounted on spring-loaded high-impact
steel bars.
• If there is a sudden pressure increase the door moves
out a small distance to release the excess pressure,
then reseals.
• Integrated safety switches cut off microwave power in
the event of pressure release.
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Enhanced Air Cooling
• Milestone has available a “Enhanced Air Cooling
Kit”.
• This kit contains adapters for the Ethos lab station
that direct the flow of air through the top of the
Ethos lab station and around vessels in segmented
rotors.
• Using this kit can provide more effective air cooling
after the completion of the microwave heating
process, but it is not as effective as water cooling.
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Exhaust
• Warning: In laboratories where acids and acid
vapors are not present (common to solvent
extraction or most organic synthesis applications),
there should be little or no consequence to
installing the Labstation in a dedicated (solvent
free), active fume hood.
• As with all electronics, one should take care to
never operate a microwave lab station in an
explosive atmosphere.
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4. Reaction Sensors
The Microwave is equipped with reactions sensors for
temperature and pressure control.
Temperature is measured either with
1. Direct sensor in a reference vessel, or via
2. A contact-less high sensitivity infrared sensor,
which effectively measures and controls the
temperature in all vessels.
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The ATC Automatic Temperature Control
system allows for direct continuous
monitoring and control of a reference
vessel up to 300°C.
• Easy and rapid insertion and removal of the
sensor
• No sensor bending
• Triple layer of PTFE/ceramic/PTFE
protection
A- Direct Temperature Control
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B- Contact-less Temperature Control
• Contact-less temperature control in all vessels
• The Microwave features a focused, high
sensitivity
• Infrared sensor for contact-less temperature
monitor and control of all vessels, with
individual temperature profiles for each vessel.
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C- Direct Pressure Control
• The APC Automatic Pressure Control system allows for
direct monitoring and control of a reference vessel up
to 100 bar.
• Pressure control up to 55bar
• Pressure monitoring and control are ideal for highly
reactive organic samples or ‘unknowns’, and for
method development, to maintain pressure limits
within the vessel’s specifications.
• Solid state sensor with built-in electronics fully
protected from acid vapors
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D- Automatic Gas Detector NOX
• NOX are released if vessels vent
• Monitoring the NOX presence in the microwave cavity allow
safer working conditions and consistant results
• This sensor continuously monitors the concentration of acid
vapors in the microwave cavity.
• Onceover a preset level, the sensor automatically adjusts the
microwave power, to effectively limit the pressure in each
vessel and prevent overpressure and venting.
• All vessels in the cavity are monitored simultaneously.
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5. Microwave Digestion Rotors MDR
a) High Pressure Rotor
b) Medium Pressure Rotor
c) Medium Pressure High Throughput Rotors
d) High Temperature Rotor
e) High Throughput Rotor
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TFM Features
• Trade name for chemically modified PTFE poly tetra
fluoro ethylene
• Dense structure
• Chemically inert
• Thermal insulator
• Microwave transparent
• Melting range 320-340°C
• Maximum working temperature for extended use
260°C, for short time 300°C
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a- High Pressure Rotor (SK10)
• High pressure rotor suitable for all samples,
including difficult organic and inorganic refractory
materials
• Ensures complete digestion of larger amounts of
highly reactive organics, such as food/feed, oils,
plastics, pharmaceuticals.
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b- Medium Pressure Rotor (SK 12)
• General purpose rotor suitable for most samples.
• The high-strength rotor body holds multiple digestion
vessels made of high purity TFM.
• Allows for the complete digestion of water, sludge,
municipal waste, biological materials, metals and
alloys.
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C- Medium PressureHigh Throughput Rotors (PRO 16/24)
• High throughput rotors suitable for easy organic
samples or environmental applications,
according to the U.S. EPA method 3051A.
• Easy handling and rapid cooling capabilities.
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d- High Temperature Rotor (Nova 10)
• High temperature rotor able to withstand extremely
high temperatures for long lasting complete
digestion of the most challenging samples.
• Suitable for very difficult inorganic materials such as
silicon carbide, metal oxides, geological, and
refractory materials.
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e- High Throughput Rotor (Multiprep)
• High throughput carousel, able to perform easy
digestions or leaching-type reactions on a variety
of samples, such as soils, sediments, wastewater
etc.
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Rotors VS Application fields
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Rotors Specifications
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6. The Vessel
Milestone ‘vent-and-reseal’ vessels are the
foundation of it’s microwave digestion
technology.
Milestone offers a wide variety of vessels for all
applications from digestion, synthesis, extraction,
evaporation, fusion, and protein hydrolysis.
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Advanced Vessel Technology
• ‘Vent-and-reseal’ vessels are the foundation
of Milestone’s microwave digestion
technology.
• Continuously enhanced, this patented*
technology provides analysts with
unsurpassed performance capabilities.
• Highest temperature and pressure
• Highest safety standards
• Easy of use
• Fast air cooling
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The Segment components
A vessel that contains the sample,
A vessel cover that seals the vessel and acts as a
overpressure release valve,
A safety shield that surrounds the vessel and provides
structure and safety for operation at elevated
pressures,
A pressure adapter plate, that fits on top of the vessel
cover,
A spring rated to the pressure performance
specifications of the particular vessel/rotor
combination, and
A vent indicator ring.
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The Vessel Material
• Microwave transparency
• Chemical resistance
• Extrusion capability (thermoplasticity)
• Machining capability
• High working temperature
• High density (low porosity)
• Thermal insulation
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Cleaning Vessels and Covers
• The simplest method for cleaning vessels and covers is to process
a blank (acids or solvents) under the same process conditions
(reaction parameter profile) that is used for preparing the
analytical samples.
• Another traditional method for cleaning vessels and covers is to
soak them in an acid or solvent bath, at elevated temperature,
for an extended period of time before they are rinsed, dried and
stored.
• Typical conditions include 1:1 nitric acid and water in a Teflon
container maintained at 80 - 90 degrees for an hour or more.
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Reference Vessel(s): purpose
• The reference vessel is a specialized vessel that facilitates
reaction parameter monitoring (temperature and / or
pressure) and allows feedback process control.
• To allow feedback process control, a reference vessel must
be prepared to contain chemistry identical to any other
sample vessel being processed during the same run.
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Cleaning The Reference Vessel
• The only way to clean the reference vessel and assembled
cover is to process a blank (using the same process acids or
solvents) under the same process conditions (reaction
parameter profile) that are used for the analytical samples.
• Although the reference vessel can be cleaned using the
soaking method or by using Milestone’s trace CLEAN
system, these methods cannot be used to clean the
reference vessel cover.
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Loading Samples
• Sample materials, normally, are quantitatively introduced into a
vessel using an analytical balance.
• Acid or solvent mixtures, normally, are quantitatively introduced
into a vessel using an analytical balance or calibrated pipettes.
• Note: Sample materials should be placed into the bottom of the
vessel, not on the sides, and should be completely submerged by
the acid or solvent mixture.
• Any sample materials that stick to the sides of the vessel should
be washed down into the pool to avoid potential vessel damage.
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Minimum Volume
• The volume of liquid in the reference vessel must be sufficient to
submerge the end of the thermowell to a depth of at least one
centimeter.
• In the standard 100 mL vessels, the minimum recommended volume
is 8 mL at room temperature.
• More importantly, the thermowell must be submerged to a depth of
at least one centimeter at the maximum temperature of the heating
process.
• This fact should be taken into consideration when using liquids with a
high vapor pressure that will result in a substantial fraction of the
liquid mass in the vapor phase at the maximum temperature of the
heating process.
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Contamination Test
• Run the following program:
o 1 minute 1000 W (for 10 Vessels)
o 1 minute 600 W (for 6 or less Vessels)
• As soon as the run is finished, check the temperature of
all Vessels (must be at room temperature).
• With temperature > 50°C please make the cleaning
procedure
• The yellow TFM vessel has been contaminated by NOx
developed during strong decomposition.
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Water Cooling
• Milestone’s Segmented and monobloc rotors can be
effectively water cooled at the completion of the microwave
heating process.
• Water cooling can be accomplished by using the standard
cooling station (available from Milestone) or by simply placing
the monobloc rotor or individual segments into any
convenient container that can hold water.
• A lab sink filled with water, so that the vessels are immersed
up to the bottom of the indicator ring (a little more than three-
quarters up from the bottom of the safety shield) is
appropriate for the purpose.
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Safety 1
• External fire protection should be installed according to local regulations for equipment
operating unattended.
• If materials inside the equipment should ignite, keep the cavity closed, switch off the
equipment and disconnect the power cord or turn off the power at the fuse or circuit
breaker.
• The equipment shall not be used for heating and ventilation of laboratories.
• The equipment shall not be used as a sterilizing equipment.
• The equipment shall not be used as a medical electrical equipment.
• The equipment shall not be used for heating food and beverages.
• The equipment shall not be used for mass production.
• The equipment shall not be used in an explosive atmosphere.
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Safety 2
• The equipment shall only be operated indoors, where the altitude does not exceed
2,000 meters (1,242 feet), at temperatures between +5°C and +40°C +(41°F and +104°F).
• The maximum relative humidity is 80% for temperatures up to 31°C (87.8°F) decreasing
linearly to 50% relative humidity at 40°C (104°C).
• The equipment shall be operated in places where fluctuations of the main supply
voltage are not exceeding values of 1.10 times the nominal voltage and are not below
0.90 times the nominal voltage.
• The equipment shall only be operated in places where transient overvoltage on the
main supply are not exceeding values of overvoltage category II specified in IEC 60364-
4-443.
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Safety 3
The power supply must be protected by a residual current circuit breaker with other
current protection, interrupt capability equal or more than 4500A, nominal current 16A (a
230V) and 32A (a 115V), characteristics C-curve, residual current 30mA.
Power line must have strong earth connection.
The equipment shall only be operated in places where normally only non-conductive
pollution occurs and occasionally, however, a temporary conductivity caused by
condensation may occur.
The equipment shall not be stored or operated in places where special conditions prevail,
such as the presence of a corrosive or explosive atmosphere (dust, vapor or gas).
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Heating Process
• When an exothermic reaction drives digestion
temperature above the programmed ramp rate,
EasyCONTROL instantly shuts off microwave
power, applying it again when the temperature
falls back to the ramp rate.
• Determining the microwave power settings
appropriate for a given run, as it automatically
adjusts the power to match the number of
samples in the rotor.
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Easycontrol Software
• The terminal runs Milestone’s unique Easycontrol software, to
provide simple, user-friendly control of the microwave sample
preparation process with automatic, real-time monitoring and
feedback-based control of multiple parameters.
• Simply recall a factory stored method or create a new one;
• press ‘START’ and the system will automatically follow the user
defined temperature or pressure profile, utilizing a
sophisticated PID algorithm to regulate the microwave power.
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The Benefit of Software
On-line control of all parameters.
• Direct temperature control 20 times per second.
• Temperature driven microwave power output:
o Reaction is controlled at any temperature
o Better control of exothermic reactions.
• Same digestion quality for different sample sizes.
• One method only needed for any number of samples.
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Login
• Switch on the main switch of the
START, located on the front panel.
• The Easycontrol display will show:
• Type your identification and confirm
you with o.k.
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Program
The program page contain four minus and six icons
1. Method 2. Parameters 3. Wave 4. Run
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1. Method
The theoretical expectation of :
1. Temperature curve
2. Pressure curve
Of the reactions according the methods.
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2. Parameter
• Select the QP on “50” medium sensitivity by scrolling up or down.
• Select the “QP Check” (activated icon). Press in the window of Ventilation.
• The display will show a keyboard: Digit the time “10”, confirm by pressing OK.
• Control for permits the selection of different controls such as T1, T2,P, if only the
Thermocouple ATC-400 is installed to use T1.
• The Twist must be always ON (activated icon) when temperature sensor T1 and/or
pressure sensor P are installed.
• The Rotor control ON (activated icon) when the IRTC sensor T2 (External temperature) is
installed.
• The Start parameters always ON (activated icon) when the temperature sensor T1
(Internal temperature) is installed.
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3. Wave
• Introduce the desired Time parameters:
• Press in the window “00.00.00” of t.
• The display will show a keyboard.
• Digit in the window “00.10.00” confirm by
pressing OK.
• Introduce the desired Energy parameters:
• Press in the window “0” of E.
• The display will show a keyboard:
• Digit into the window “1000”, after confirm
pressing OK
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4. Run
Complete “on-line” control and graphic
representation of all reaction parameters
1. Time
2. Microwave power
3. Internal temperature
4. External temperature
5. Pressure
6. Acid vapors level in the microwave cavity
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Laboratory Requirements
• The lab bench can easly handle the combined weight of cmplete station “ 100 kg”.
• The exhaust hose must be connected to some source of active ventilation:
• The labstation draws a maximum of 16 amps on a 230 VAC single phase line.
• The labstation must be connected to a grounded, single phase line, with 220–230 vac output.
• Milestone recommends that all addition of acid mixtures or hazardous solvents to vessels
should take place inside an appropriately vented fume hood.
• Milestone recommends that vessels be opened inside an appropriately vented fume
hood to contain and convey reaction vapors.
• The instrument requires sufficient clearance (approximately 15 centimeters space) on all sides
of the chassis to allow adequate movement of air.
• Microwave labstation should not be permanently installed inside an active fume hood due to
the potential for acid vapors to attack and accelerate the corrosion of internal electronic.
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Sampling Method Structure
1. Summary
2. Microwave equipment
3. Sample amount
4. Reagents
5. Procedure
6. Microwave program
7. Temperature profile
8. Notes
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Example
1- SUMMARY
This method provides for the acid digestion of the Sludge sample in a closed
vessel device using temperature control microwave heating for the metal
determination by spectroscopic methods.
2- MICROWAVE EQUIPMENT
Milestone ETHOS Labstation with easy WAVE or Easycontrol software
HPR1000/10S high pressure segmented rotor.
3- SAMPLE AMOUNT 1.0 g
4- REAGENTS
8 ml of HNO3 65%, 2 ml of HCl 37%
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5- PROCEDURE
a) Place a TFM vessel on the balance plate, tare it and weigh of the sample.
b) Introduce the TFM vessel into the HTC safety shield.
c) Add the acids; if part of the sample stays on the inner wall of the TFM vessel, wet it by
adding acids drop by drop, then gently
d) swirl the solution to homogenize the sample with the acids.
e) Close the vessel and introduce it into the rotor segment, then tighten by using the torque
wrench.
f) Insert the segment into the microwave cavity and connect the temperature sensor
g) Run the microwave program to completion.
h) Cool the rotor by air or by water until the solution reaches room temperature.
i) Open the vessel and transfer the solution to a marked flask.
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6- MICROWAVE PROGRAM
7- TEMPERATURE PROFILE
8- NOTES
Use up to 500 Watt for operations with 3 or less vessels simultaneously.
This procedure is only a guideline and it may need to be modified or changed to obtain the
required results on your sample.
Always use hand, eye and body protection when operating with the microwave system.
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Acid Classification in Digestion Reactions
NONOXIDIZING
• Hydrochloric acid
• Hydrofluoric acid
• Phosphoric acid
• Diluted sulfuric acid
• Diluted perchloric acid
OXIDIZING
• Nitric acid
• Hot concentrated perchloric acid
• Concentrated sulfuric acid
• Hydrogen peroxide
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Nitric Acid
• It dissolves most metals forming soluble nitrates, exceptions are
Au and Pt (not oxidated) and Al, B, Cr, Ti and Zr (passivated)
• These metals require acid mixtures or diluted nitric acid
• Often mixed with H2O2, HCl and H2SO4
• Available in high purity for trace analysis
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Nitric Acid
• Boiling point is 120°C at 65% concentration
• Poor oxidizing strength at concentrations less than 2M; oxidizing
strength increases with concentration and reaction T&P
• Most common acid for oxidation of organic matrices
(CH2)X + HNO3 = CO2(g) + NOX(g) + H2O
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Hydrofluoric Acid
DIGESTION
• Boiling point is 108°C at 40% concentration
• Nonoxidizing, strong complexing nature
• Used in digestion of minerals, ores, soils, rocks and even botanical samples
• Major use is the decomposition of silicates
• SiO2 + 6HF = H2SiF6 + 2H2O
• Often used in combination with HNO3 or HClO4
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Hydrofluoric Acid
• EVAPORATION/CONCENTRATION
• Following dissolution, many analyses require removal of HF to
prevent equipment damage or to resolubilize insoluble fluorides
H2SiF6 = SiF4 + 2HF
• Many analytes such as As, B, Se, Sb, Hg, Cr may volatilize
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Hydrochloric Acid
• Boiling point of azeotropic mixture with H2O with 20,4% HCl is 110°C
• Available with 38% concentration
• Nonoxidizing
• It dissolves salts of weak acids (carbonates, phosphates) and most
metals are soluble with the exception of AgCl, HgCl and TiCl
• Excess of HCl improves the solubility of AgCl, converted into AgCl2-
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Hydrochloric Acid
• Strong complexing nature
• Widely used for iron-based alloys because of its ability to hold
large amounts of chloro-complex in solution
• Other complexes formed are Ag (I), Au (II), Hg (II), Ga (III), Tl
(III), Sn (IV), Fe (II) and Fe (III)
• It does not dissolve oxides of Al, Be, Cr, Ti, Zr, Sn and Sb;
sulphates of Ba and Pb, group II fluorides, SiO2, TiO2 and ZrO2
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Sulfuric Acid
• Boiling point is 340°C at 98% concentration, exceeding max
working temperature of Teflon vessels
• Careful reaction temperature monitoring is required to prevent
vessel damages
• It destroys organics by dehydrating action
• Many sulfates are insoluble (Ba, Sr, Pb)
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Perchloric Acid
• Boiling point is 203°C at 72% concentration
• Powerful oxidizing acid when used warm
• Hot and concentrated decomposes violently organic matter
• Nearly all perchlorates are soluble
• HClO4 decomposes at 245°C in microwave closed vessel with
dangerous amounts of by-products and tremendous excess
pressure
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General Rules for Usage of Perchloric Acid
• Rule #1: do not use it conc.
• Use only very diluted perchloric acid
• Mix it with other acids (but never with sulfuric acid)
• Never exceed 200°C
• Use it only to perform a two-step digestion
• Perchloric acid is normally not required for the closed vessel
microwave digestion of organic samples
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Hydrogen Peroxide
• Oxidizing agent
• 2H2O2 = 2H2O + O2
• Added to HNO3 it reduces nitrous vapors and it
accelerates the digestion of organic samples by raising
the temperature
• Typical mixture ratio is HNO3:H2O2=4:1
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Rules 1
• All vessels must contain same type and amount of sample/reaction mixture.
• The minimum and maximum volumes are set in accordance with the rotor
specification.
• The maximum volume must be approximately 50/60% of the total volume of the
vessel.
• Never use a blank in the reference vessel.
• Never heat water in the reference and/or in one of the standard vessels.
• Before adding reaction mixture rinse the vessels with distilled water in order to
remove any electrostatic field.
• To prevent hot spot place the sample on the bottom of the vessels, if part of the
sample stays on the inner wall of the vessel, wet it by adding acids drop by drop.
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Rules 2
• If during the addition of the reagents at your sample an exothermic reaction is observed,
leave the vessel under fume hood for five minutes, before closing.
• Before running any test check that the method (temperature and pressure) is suitable for
your type of reactor.
• For strong exothermic reactions add 2 ml of distilled water.
• Periodically check the status of vessels, covers, shields, adapters, springs.
• After starting the microwave program always check if the temperature and/or pressure
sensor are free to rotate.
• Never open the reaction vessels at high temperature or above the boiling temperature of
the reagents
• Do not use ice to cool down the rotor after microwave heating as the thermal shock could
damage the safety shields.
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Basic Method Optimization
POOR DIGESTION QUALITY
• Increase T1 of the two last program Steps in 10°C increments.
• Extend Time of the last step.
• Reduce weight and / or increase quantity of chemicals /concentration of acids.
• Optimize acid mixtures particularly with inorganic samples.
• Use stirrer.
• With good quality of digestion, the last program step can be reduced
• For method development use a small sample amount (e.g. 100 mg), low temperature,
low power and short time
86
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Approved Methods
• ASTM (American Society of Testing and Materials) Methods
• USCPSC (US Consumer Product Safety Commission) Methods
• US Pharmacopeia Methods
• U.S. EPA Methods
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Applications
• Food/Feed
• Environment
• US EPA methods
• Clinical/Pharmaceutical
• Petrochemical
• Plastic/Polymer
• Metal/Alloy
• Geochemistry/Mining
• Ceramic/Refractory
• Various
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Application Table
Applications NO. Applications NO.
Food/Feed 72 Plastic/Polymer 15
Environment 45 Metal/Alloy 50
High temp. rotor 12 Geochemistry/Mining 71
Clinical/Pharmaceutical 25 Ceramic/Refractory 24
Petrochemical 21 Chemicals 18
Agriculture 9 Catalyst-pigment 12
