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Revista de cliente "a amostra" (13)

No. 32
SAMPLE PREPARATION for Instrumental Analysis
No. 36
The Art of Milling - Contemporary Milling Technologies
No. 34
PRODUCT NEWS'09
No. 37
NEW DIMENSIONS in sample preparation and particle analysis

No. 35
Novidades de produtos no teste prático
No. 33
SAMPLE PREPARATION IN PRACTICE & NEW RETSCH INSTRUMENTS
No. 31
Grand Prix Season 2008 & New RETSCH Instruments
No. 30
Mills and Particle Analyzers for Environmental Analysis
No. 29
New Product Generation 2007
No. 28
Think big but grind fine!
No. 26
CAMSIZER - Optical Particle Size and Shape Analysis
No. 25
Retsch presents the new Ultra-Centrifugal Mill ZM 200
No. 24
Anniversary issue of the RETSCH customer magazine 10 years "the sample"

Relatos técnicos (43)

Representative results require adequate sample preparation
The following situation is typical for many production plants: After a routine quality check, the production process is stopped or an already produced batch is suspended, because the analysis results were not within the relevant critical values. But does the tested product really deviate from the specifications? The quality control managers are convinced of this because modern analysis instruments provide results with very low tolerances. The sample in question was tested several times and the result was confirmed. The question is why the product does not match the specifications although the production parameters have not been changed in any way.
The possibility that the tested product is indeed deficient cannot be excluded. However, it is often not the product itself which causes irregular analysis results but a lack of understanding of the steps which come before the analysis.
Renewable energies on the rise
Sample preparation of vegetable-based raw materials with laboratory mills

Thanks to the increasing usage of biomass as a source of energy, the analysis of these materials in the context of R&D and quality control gains importance, too. Due to the complex properties of plant materials, adequate sample preparation can be rather a challenge.
Detection of Mycotoxins in Nuts
Preliminary and fine size reduction
Toxic analyses of biological samples
Cryogenic grinding facilitates the preparation of animal samples
Sample Preparation for XRF Analysis
From sample to pellet
Molienda ultrarrápida y ultrafina
El nuevo molino ultracentrífugo ZM 200 de RETSCH es un molino de rotor no sólo extremadamente rápido y cuidadoso con el material molido, sino también de uso universal gracias a su amplia gama de accesorios.
Höchstleistung im Doppelpack
Mit der PM 100 und der PM 200 präsentiert Retsch eine neue Generation von Planeten-Kugelmühlen mit einer bzw. zwei Mahlstellen, die in diesem Produktsegment neue Leistungsstandards setzen.
Size reduction within the context of sample preparation
In general “size reduction” is taken to mean the disintegration of solid substances by mechanical forces without altering their state.
Sick with Dolls
Traces of Heavy Metals in Toys
Recycled glass - a valuable resource
Today, recycled glass is the most important resource for the glass industry. The processed glass can be reintroduced to the melting process any number of times and made into new products. In Germany, currently up to 95 % of recycled glass is used for producing glass, which has various advantages: energy saving, less consumption of primary raw materials (such as lime and silica sand) and the reduction of landfill costs for waste glass.
Scrap turned into raw materials: End-of-life vehicles re-used
The EU directive 2000/53/EG stipulates that as of 2015 95 % of the weight of a car that has reached the end of its life span have to be recycled. The work of ARN is strongly focused on this objective. Together with partner companies they make sure that old cars are processed in an environmentally compliant way. The recycling chain begins with the companies that dismantle the car and remove raw materials and liquids. Waste management companies collect these materials and deliver them to the processing companies who reuse the materials in accordance with high production standards.
Repräsentative Probenvorbereitung im Umweltlabor
Die Vermeidung von Umweltverschmutzung ist eines der zentralen Themen in den Industriegesellschaften des 21. Jahrhunderts. Eines der wichtigsten Instrumente in diesem Zusammenhang ist die regelmäßige Kontrolle mit modernen analytischen Methoden. Neben Luft- und Wasseranalytik stehen Altlastensanierungen und Deklarationsanalysen ebenso im Fokus wie die Analytik von Boden, Bauschutt, Sedimenten, Altholz, Sekundärbrennstoffen u.v.m.. Für nahezu sämtliche chemische und physikalische Analysenmethoden ist es notwendig, die Analysenprobe in einem möglichst hohen Grad zu homogenisieren und sie auf eine definierte Feinheit zu zerkleinern. Hierbei erstreckt sich die notwendige Probenvorbereitung auf alle Proben der unterschiedlichen Matrizes. Die Probenvorbereitung hat somit neben der Probenahme einen entscheidenden Einfluss auf das Analysenendergebnis, denn: Probenvorbereitungsfehler können das Endergebnis um mehr als 50% beeinflussen!
Representative Analysis Results Require Adequate Sample Preparation
A faultless and comparable analysis is closely linked to an accurate sample handling. Only a sample representative of the initial material can provide meaningful analysis results. Rotating dividers and rotary tube dividers are an important means to ensure the representativeness of a sample and thus the reproducibility of the analysis. Correct sample handling consequently minimizes the probability of a production stop due to incorrect analysis results. Thus correct sample handling is the key to effective quality control.
CryoMill - Cryogenic grinding was never more convenient or efficient
Some sample materials have properties which make size reduction at ambient temperature impossible. If, for example, very elastic materials need to be ground or volatile components have to be preserved for further analysis, it is essential to carry out cryogenic grinding. The use of liquid nitrogen helps to embrittle the sample, thus improving its breaking properties, and preventing volatile substances from escaping due to the frictional heat produced by the grinding process.
Vermahlungen ohne Verlust von Inhaltsstoffen
Kryomühle im Einsatz an der BTU Cottbus
Bei vielen Materialien ist es vorteilhaft eine Kryomühle für die Zerkleinerung einzusetzen, statt einer Labormühle, die bei Raumtemperatur arbeitet. Die Probe wird durch den eingesetzten flüssigen Stickstoff versprödet und kann darum besser durch Schlag, Druck und Reibung zerkleinert werden; außerdem bleiben leicht flüchtige Bestandteile erhalten. An der Brandenburgischen Technischen Universität (BTU) Cottbus ist eine Kryomühle in den Bereichen Kunststoffrecycling und Biomaterialien im Einsatz.
Silicon for solar energy
Semiconductors are used for a variety of electronic applications such as integrated circuits (microprocessors, microcontrollers etc.), optical detectors and radiation sources (e. g. light emitting diodes), but particularly for photovoltaics where solar energy is transformed into electrical power. For the majority of applications, silicon is the semiconductor material of choice.
Renewable energy
Wood residues from forestry work and wood processing are usually processed to wood chips. These can be used in different ways, depending on the type of wood, bark and residual moisture, for example as raw material for chipboards or as substrate for the cultivation of mushrooms. The major part, however, is used for energy generation. The quality of the wood chips can vary significantly, depending on their origin and condition. Trade and industry are interested in the percentage of dry matter and in the calorific value of the chips as the price calculation depends on the water contents of the product. With the analysis result representing an important economic factor, the representative and reproducible sample preparation gains importance, too.
Schnell und schonend zerkleinern
In zahlreichen Labors werden täglich viele unterschiedliche Probenmaterialien aufbereitet. Für die Zerkleinerung von Feststoffproben auf Analysenfeinheit wird eine Mühle benötigt, die nicht nur vielseitig einsetzbar und leicht zu reinigen ist, sondern die auch eine reproduzierbare Probenvorbereitung – und damit zuverlässige Analysenergebnisse - garantiert.
Mit der Ultra-Zentrifugalmühle ZM 200 bietet RETSCH eine Rotormühle an, die nicht nur sehr schnell, sondern auch äußerst materialschonend zerkleinert und, dank einer umfangreichen Zubehörpalette, universell einsetzbar ist. Mit ihrem kraftvollen Powerdrive-Antrieb vermahlt die ZM 200 weiche bis mittelharte und faserige Materialien extrem schnell auf Endfeinheiten bis unter 100 µm und steigert so den Probendurchsatz im Labor.
Cutting Mill SM 300 - Refinement of a well-proven grinding principle
Cutting mills are used in many different areas of sample preparation for subsequent analyses. Typical applications include the size reduction of secondary fuels, the processing of biomass for renewable energy research, the control of products in the context of RoHS and WEEE regulations or the recovery of precious metals – the variety of sample materials is huge.
Powerful Cutting Mill
The SM 300 excels especially in the tough jobs where other cutting mills fail. It has a freely selectable speed range from 700 to 3,000 rpm with high torque. The mill is convenient to operate and easy to clean. Reliable and extremely efficient sample preparation in the laboratory is now guaranteed with the SM 300.
Probenvorbereitung von Böden
Bestimmung von anorganischen Inhaltsstoffen in Bodenproben

In Industrienationen mit hoher Besiedlungsdichte und einem begrenzten Angebot an Industrie- und Gewerbegebieten unterliegt die Nutzung von Gebäuden und Flächen einem dauerhaften Wandel. Daher sind Bodenuntersuchungen für Investoren, Behörden und Privatpersonen unumgänglich. Umweltanalytische Untersuchungen bilden die Basis, um Gefährdungen aufzuzeigen und damit Menschen und eingesetztes Kapital zu schützen. Bei SGS Institut Fresenius in Herten werden bis zu 400 Bodenproben am Tag aufgearbeitet und analysiert. Hierbei wird sehr genau darauf geachtet, dass geltende Normen und Verordnungen eingehalten werden. In Deutschland gilt die BbodSchV, wobei die Analytik auch auf die Vorschriften anderer Länder angepasst wird.
Using the CryoMill for samples with volatile substances
For the size reduction of many materials it is more suitable to use a cryogenic mill than a laboratory mill which operates at room temperature. The sample is embrittled by liquid nitrogen which improves its breaking behavior when submitted to impact, pressure and friction; moreover, volatile components of the sample are preserved. The RETSCH CryoMill is not only the most modern and safest cryogenic mill in the market, it also provides excellent grinding results.
Preparation of Elastic Plastics for the Detection of PAH
Polycyclic aromatic hydrocarbons, short PAH, are usually a by-product of combustion and can be found, for example, in cigarette smoke or oil-based products. Mineral oil containing PAH is often used in rubber products as plasticizer, especially in black-coloured products such as car tyres, rubber grips of tools or rubber shoe soles. It was discovered that some polycyclic aromatic hydrocarbons are carcinogenic, so that maximum permissible values have been determined for the concentration of PAH in consumer products.
Efficient Grinding at –196 °C
RETSCH’s New CryoMill for Safe and Reproducible Grinding with Liquid Nitrogen
Preparation of Soil, Sewage Sludge and Sediment Samples in a Wastewater Treatment Laboratory
The preparation of a mixture of organic and inorganic samples holds some difficulties: whereas sand, clay and stones can usually be ground to homogeneous samples with suitable laboratory mills, the high energy input can cause samples with organic components such as fat or starch to cake. Carsten Bunn, a laboratory technician at the waste water treatment laboratory BRW, has to deal with this problem every day. He treats samples which are taken from the sand traps of the wastewater treatment plants and consist of exactly that mixture. The sediments of household and industry waste water not only contain sand, clay or leaves but anything that people nowadays dispose of through the sewer system: cellulose, hair and especially food residues.
Green Chemistry in the Lab
Mechanochemistry is a very effective method to carry out syntheses without solvents and by-products. The technical literature describes a great number of reactions where a conversion of 100% is achieved. A precondition for the establishment of mechanochemistry in the industrial sector is the availability of suitable laboratory mills. A decisive factor is that – similar to conventional preparative chemistry – ambient parameters such as pressure and temperature can be documented and monitored. The Planetary Ball Mills and Mixer Mills from Retsch fulfill these requirements.
Tracking down hazardous substances (RoHS/WEEE)
Preparing electronic waste for obtaining representative analytical samples.
A solution for converting an electrical appliance into a meaningful analytical sample is described using a remote-controlled toy car as an example.
Sample preparation of electronic scrap with SM 2000 and ZM 200
RETSCH mills in the context of RoHS and WEEE
Cryogenic Preparation of Sample Materials
Within the context of sample preparation, size reduction plays an important role as it has a substantial influence on the results of the subsequent analysis. If the particles are too coarse or non-homogeneous the results of the analysis may turn out to be incorrect, especially if there is only a very small amount of sample material which represents the total amount.
The preparation of samples of solid substances for spectroscopic analysis
X-ray fluorescence spectrometry is one of the most versatile multi-element methods of chemical analysis. The technique is based on excitation of fluorescent radiation from a sample by bombarding it with high energy X-ray quanta and subsequent study of the characteristic X-ray radiation emitted by its elements.
Reliable sample preparation in food technology
An efficient sample preparation procedure for rapid, reliable and reproducible analytical results is becoming increasingly important today. Ever more stringent requirements are being set both in research and production, e.g. for product monitoring and quality control.
The Representative Sample Preparation of Waste
Now that a certain environmental awareness has developed in the population over the past few years, our efforts are geared not only to avoiding waste, but also to reducing the mountains of waste which still arise by means of raw material recovery and the reintroduction of secondary raw materials into the industrial cycle.
Representative Sample Preparation to Environmental Analysis
The prevention of environmental pollution is a prime issue of today’s industrialized societies. Important instruments in this context are regular checks using the latest analytical methods. Beside air and water analysis the focus is also on environmental remediation and declaration analyses as well as examination of soils, construction waste, sediments, secondary fuels and many more. Prevention and ecological recycling and disposal are the key words of a modern environmental policy. If the production of waste cannot be prevented, the primary objective is its material or energetic recycling. Residuals which cannot be recycled have to be disposed of in an ecologically friendly way.
Secondary fuels – Energy for the cement industry
Due to decreasing resources and increasing market prices for primary fuels like oil, gas or coal, it is paramount for the cement industry to search for alternative energy sources. With regard to the CO2 emissions trading, a switch to energy sources which have a neutral CO2 balance can be rather profitable. Usually, these are non-fossil fuels. Industries with high energy consumption have made increasing use of alternative fuels during the last years. Accordingly, the use of so called secondary fuels (also waste derived fuels/wdf or refuse derived fuels/rdf) has gained importance. These are mostly combustible fractions of domestic or industrial waste which cannot be recycled.
Size reduction of elastic plastics with volatile components
Neutral-to-analysis sample preparation for the detection of PAH and phthalates
Fast and Reproducible Sample Preparation with a Vibratory Disc Mill
The Vibratory Disc Mill RS 200 from Retsch is used for the quick, loss-free grinding of hard, brittle and fibrous materials to analytical fineness.
Cement - representative sample preparation is important
To produce high-quality cement, the mineralogical and chemical composition of raw materials as well as intermediate and finished products has to be determined. At each stage of the production, samples have to be taken, processed and analysed to ensure quality control without gaps. Retsch offers a range of instruments that are used for sample preparation during the complete production process, from the quarrying of the raw materials to the final product. The typical sample preparation process involves preliminary size reduction, sample division and fine size reduction before the sample can be submitted to further analyses....
Sample Preparation of Electronic Scrap in the Context of RoHS and WEEE
Since August 2004 new EU directives for the disposal of used electrical and electronic appliances as well as the restricted use of certain hazardous substances in these devices have become effective.
Sample Preparation of Plastics for X-Ray-Fluorescence Analysis
The elemental analysis of plastics has become more and more important. EC directive 91/338/EWG regulates the ban of cadmium in PVC, EC directive 94/62/EC defines limits for cadmium, lead, chromium and mercury in packing materials and EC directive 2000/53/EC defines limits for the same elements in end-of-life vehicles. This has created a strong need for a rapid and reliable testing method.
Analysis of cadmium in plastics
In recent years, mass media have focused on the topics of the environment and environmental conservation. With the advancement in scientific technology, resource development has progressed.
Separation of large sample volumes with the AS 450 control
Particle analysis of large quantities of bulk goods is usually done by vibratory sieving. In most vibratory sieve shakers in the market the sieve stack is mounted
on springs which oscillate vertically. However, to evenly distribute the material
over the entire sieve surface, the so called 3D vibratory sieving as it is used in the AS 450 control is the most suitable method. This is characterized by a circular
motion superimposing the vertical throwing motion so that the sample material
is moved over the whole sieve.
Sieving of agglomerating powders with the air jet sieving machine AS 200 jet
Air jet sieving is usually the method of choice for dry sieving of materials with particle sizes below 40 microns. However, it is also a faster alternative to vibratory sieving of materials of up to 250 microns.
Air Jet Sieving of Bulk Materials
Particle size analysis and particle size distribution are important criteria for the quality  control of bulk materials. In a running production process, the results of a quality check must be available quickly to allow for immediate adjustment of the production parameters. Depending on the expected particle size and sample volume, different sieving methods and sieving machines are suitable for analysis. The method used for particle size analysis is primarily determined by the fineness of the material to be sieved. For dry sieving of samples with particle sizes below 40 microns, air jet sieving is the method of choice.

Boletins de imprensa (3)

  • Versatile Ultra Centrifugal Mill with New Cyclone

    RETSCH’s powerful and versatile ZM 200 offers the ultimate in performance and operating comfort. It is used for the rapid size reduction of soft to medium-hard and fibrous materials down to 40 microns. Because of the efficient size reduction technique and the comprehensive range of accessories the ZM 200 ensures the gentle preparation of analytical samples in a very short time.
    For applications which require an optimum air throughput (e. g. heat sensitive materials) or if larger sample volumes need to be processed, the use of a cyclone is recommended. RETSCH offers a re-designed cyclone with improved functionalities for collector volumes from 250 ml to 5 liters which adds to the ZM 200’s great flexibility.
    Thanks to the wide range of accessories with different rotors, ring sieves and collectors, the ZM 200 can be easily adapted to suit a wide range of applications such as, for example, heavy-metal-free grinding, size reduction of abrasive materials or processing small volumes up to 20 ml.

  • Neue Zyklonmühle für die Probenvorbereitung zur NIR Analytik

    RETSCH hat die Zyklonmühle TWISTER speziell für die Probenvorbereitung von Lebens- und Futtermitteln entwickelt, die anschließend mittels NIR analysiert werden. Die optimierte Form des Rotors und des Mahlraums erzeugt einen Luftstrom, der das zerkleinerte Mahlgut durch den integrierten Zyklon in das Probengefäß überführt. Der Luftstrom verhindert gleichzeitig ein Erhitzen der Probe, so dass Feuchtigkeitsverluste vermieden werden. Die im Lieferumfang enthaltenen Siebe garantieren eine optimale Partikelgrößenverteilung, was eine Neukalibrierung des NIR-Spektrometers überflüssig macht. Die Rotorgeschwindigkeit ist in 3 Stufen einstellbar und lässt sich somit an die Anforderungen der Probe anpassen. Der Reinigungsaufwand ist beim TWISTER sehr gering, da die Probe praktisch vollständig aus dem Mahlraum ausgetragen wird. Diese neue Zyklonmühle in bewährter RETSCH-Qualität optimiert die reproduzierbare Probenvorbereitung für die NIR Analytik und ermöglicht somit aussagekräftige Analysenergebnisse.
  • Cyclone Mills

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