Categories
Blogs

Sample preparation by microwave assisted closed vessel digestion

Sample preparation by microwave assisted closed vessel digestion for determination of elemental impurities based on USP chapter 232 and 233

 

 

Introduction

After long decades relying on old-fashion comparative visual measurements based on formation of metal ions precipitate with sulfide, all strategies for determination of metals in pharmaceuticals are changing based on new USP 232 (Elemental Impurities – Limits) and USP 233 (Elemental Impurities – Procedures) protocols. Nowadays, there are efforts towards harmonization of legislation among USP, European Community, Japan and other pharmacopeias and it seems clear that metals determination will strongly rely on microwave-assisted closed vessel digestions and determinations using ICP-based techniques, i.e., ICP OES and ICP-MS. This is clearly affecting the pattern of papers published in the area and they are moving from specific applications considering type of samples and analytes to general procedures with analytical capability for determining many analytes in several types of samples. Efforts in this direction are underway and there is plenty of room for the development of microwave-assisted digestion procedures. The development of these procedures will be critically dependent on the choice of the acid digestion mixture and the use of closed vessels to support high pressures and, consequently, allowing operation at high temperatures.

Materials & Methods

In our everyday lives, people are exposed to a variety of chemical substances, some of which may be harmful to their health at relatively low exposure concentrations. The use of toxic substances may be banned or restricted by national or international authorities, according to the outcome of substance- and exposure-specific risk assessment. ‘‘Heavy metals’’ have been the subject of elaborate toxicological research, which has led to subsequent efforts to limit human exposure to several toxic metals. Such efforts include the formulation of guidelines stating limit concentrations in consumer products, food and beverages, drinking water and environmental compartments.

 

Recently, USP has published proposals for new general chapters concerning limit concentrations of various elemental impurities and proposed new analytical procedures to accurately determine them at the suggested limit concentrations. The respective documents,4,5 which are currently in the process of revision, are Chapters 232, Elemental Impurities – Limits, and 233, Elemental Impurities – Procedures. For Chapter 232, target elements were selected on the basis of toxicity and limit concentrations were calculated based on permitted daily exposure for a person with a body weight of 50 kgs.

 

Depending on the analytical procedure adopted and sample analyzed, acid types and concentrations used were either 1% (v/v) HNO3, 10% (v/v) HNO3 or one of following mixtures of HCl and HNO3: 6% (v/v) of a 5 : 1 HCl : HNO3 mixture, 2% (v/v) of a 1 : 1 HCl : HNO3 mixture, 10% (v/v) of a 3 : 1 HCl : HNO3 mixture or 10% (v/v) of a 1 : 3 HCl : HNO3 mixture. As indicated, microwave-assisted acid digestion was performed to aid in sample dissolution, using a Milestone Ethos UP System.

Quality Analysis with great sample preparation

The new ETHOS UP is simply the most advanced yet easy to use system for microwave sample preparation we have ever manufactured. It offers a perfect integration between microwave hardware, user interface, digestion sensors and pressure vessels.

 

The ETHOS UP fully embodies Milestone’s philosophy in microwave sample preparation. Specifically designed for closed vessel microwave acid digestion, it offers productivity, safety, ease of use, connectivity, expertise and application flexibility.
Featuring a comprehensive choice of accessories, ETHOS UP microwave digestion system encompasses Milestone’s visionary concept of “Total Microwave Sample Preparation” offering a complete first-class solution for microwave solvent extraction, high-temperature fusion, vacuum evaporation and even organic and inorganic synthesis or protein hydrolysis.

  • Safety and reliability.Best microwave hardware, temperature and pressure sensors
  • Performance and throughput.easyTEMP temperature control and advanced rotor technology
  • Ease of use and control.EasyCONTROL operating software
  • Expertise and know-how.30-years experience at your lab with the Milestone Connect
  • Rotor-based digestion system for hundreds of applications.

SAFETY AND RELIABILITY IN SAMPLE PREPARATION

The ETHOS UP fully embodies Milestone’s philosophy towards, and knowledge of, microwave sample preparation. Specifically designed for closed vessel acid digestion, it offers a perfect integration of microwave hardware, user interface, reaction sensor technology and pressure resistant vessels. The ETHOS UP is the most powerful system in the market, with two magnetrons and a total power of 1900 Watts. Microwave homogeneity is assured through a dedicated microwave diffuser. Safety and reliability are Milestone’s priorities. Both factors are ever present in the foundation of the ETHOS UP’s design. The cavity has a volume in excess of 70L, and is constructed entirely of stainless steel to ensure longevity and structural integrity. Our unique pressure responsive door, also made of stainless steel, ensures superior safety even with the most reactive samples. The safeVIEW high definition digital camera, allows to safely look into the microwave cavity.

SK-15 ROTOR

Regardless of the samples you’re trying to digest, the Milestone SK-15 rotor is always an effective option to simplify your journey from sample to analysis, even with hard-to-digest samples. The SK-15 is a high- pressure and high-temperature rotor with a capacity of up to 15 PTFE vessels of 100 mL suitable for digestion of polymers, large food and feed samples, pharmaceuticals, alloys and geological materials. The table shows the recovery study with the SK-15 on pharmaceutical samples. The simplified design of the rotor coupled with its large vessel capacity ensures high productivity without compromising on performance. Safety is assured by our unique vent- and-reseal technology, the foundation of Milestone’s position as the leader in closed vessel microwave digestion. Milestone has recently evolved this already advanced technology (US Patent 5,270,010), providing the operator with unsurpassed safety and performance capabilities by further increasing the temperature and pressure capacities of the vessels. A safety spring built into the cover allows for precise venting of the vessel, if that should occur. Once the pressure has been reduced to a containable level, the cover closes again. Only the excess pressure, mainly generated by CO, NO, fumes, is therefore released, allowing for a complete recovery of even volatile elements.

THE LARGEST STAINLESS-STEEL MICROWAVE CAVITY

The microwave cavity has a volume of over 70 liters, the largest currently available. Therefore, digestion rotors with more sample places can be accommodated, incresing both productivity and sample throughput. Secondly, it improves the inherently safety because a larger cavity contains gases escaping from vessels in a more efficient way, in case of a sudden over pressurization.

PRESSURE-RESPONSIVE DOOR FOR MAX SAFETY

For additional safety, the ETHOS UP features a full stainless steel door with an innovative opening and self-resealing mechanism. Should there be a sudden over pressurization of the cavity, the door slightly opens for rapid and safe pressure release and the microwave power is instantaneously cut off. Immediately afterwards, the door is pulled back, resealing the microwave cavity.

THE MOST POWERFUL MICROWAVE DIGESTER

The ETHOS UP is equipped with two 950 Watt magnetrons for a total of 1900 Watt. The system additionally employs a rotating diffuser that evenly distributes the microwaves throughout the cavity. High power coupled with this diffuser enable very fast heating of high throughput rotors and the complete digestion of the most difficult samples.

LIVE MONITORING WITH MILESTONE SafeVIEW

The ETHOS UP integrates the Milestone safeVIEW, a high definition digital camera interfaced with the instrument terminal. It allows the chemist to monitor the progress of the digestion whilst being fully protected by the instrument’s all-stainless steel door. A video of the entire run is shown in real time.

SMART SOFTWARE
to save your time

 

  • Hundreds of methods factory stored
  • Visual indication of temperature and pressure values
  • Methods and runs printed or saved as PDF files
  • Instrument’s trail tracking (CFR-21 Part 11 compliance)
  • Easy-to-read, bright, full-color, touchscreen display
  • Icon-driven, multi-language software

Temperature control with easyTEMP

The easyTEMP contactless sensor directly controls the temperature of all samples and solutions, providing accurate temperature feedback to ensure complete digestion in all vessels with superior safety. This technology combines the fast and accurate reading of an in-situ temperature sensor with the flexibility of an infrared sensor.
The ETHOS UP software provides digestion history traceability and temperature measurement for every sample. Temperature diagrams and profiles are displayed in real-time, and can be saved on the ETHOS UP terminal.

30 YEARS OF EXPERIENCE MILESTONE CONNECT AT YOUR FINGERTIPS

Milestone Connect is a unique feature for your best-in-class system putting Milestone 30-years of applications experience at your fingertips.
By choosing ETHOS UP, ETHOS EASY, ETHOS LEAN, ultraWAVE or DMA-80 evo, you will get exclusive access to the knowledge and experience of the Milestone scientific community and application team: continuously updated application notes, library of scientific papers, video tutorials, system manuals are available at any time – 24/7. The Milestone Connect can remotely monitor the operation of your microwave digestion system or direct mercury analyzer through your desktop, tablet or smartphone device, thus enhancing your enhancing your sample preparation or analysis procedure.

 

 

Unique customer resource center

Solid experience combined with perfect technologies to remotely monitor functionality of equipment helped our application team to develop Milestone Connect. Milestone 30-years of experience are perfectly realized in Connect product – ideal solution for forward-looking laboratories willing to have more knowledge and use cutting-edge instruments.
By logging-in, they will be able to be part of Milestone scientific community and tap into unlimited resources. Milestone know-how and 30-year experience in sample preparation are now available for chemists to provide with instant support available 24 hours a day, 7 days a week.

Categories
Blogs

Juicing Juice: Determining Protein with the FP928

Juice’s popularity continues to rise year after year. Juice has risen to the forefront as a sustainable, vegan, and nutritious beverage option as consumers become more health- and environmentally-conscious. It doesn’t hurt that, as a result of the pandemic, people have shifted to entertaining at home and making their own mixed drinks with juice as mixers. But how does juice fare in terms of nutritional value?

Fruit juice does not always meet all of the nutritional requirements. Some sugary juices are actually losing popularity, as evidenced by PepsiCo’s sale of their Naked and Tropicana holdings. Juices that incorporate vegetables and other nutritional ingredients while maintaining light and fruity flavours are becoming increasingly popular.

Light, dairy-free drinks high in protein have seen a significant increase in demand. For more than just meat substitutes, plant-based proteins are seen as a more sustainable and humane alternative to animal-based proteins. Adding protein to a juice requires much more than simply stating that protein is present.

Measuring the amount of protein in the juice is an important step in the juice-making process. This is a type of quality control and process monitoring, as well as something that is required for nutritional labels and claims. It’s a task made easier by tools like LECO’s FP928 Nitrogen/Protein Analyzer.

This application note explains how the FP928 can quickly and accurately determine the protein content of juice samples.

Categories
Blogs

Automating Better Water: The TGA and Water Treatment

Automating Better Water: The TGA and Water Treatment. Clean, safe water is essential to life, and the ability to properly process and treat wastewater is critical to environmental preservation. As a result, water treatment plants like Veritas S. p. A (Veneziiana Energia Risorse Idriche Territorio Ambiente e Servizi) are an important part of water infrastructure, and the analytical methods they employ are an important part of water treatment. 

Veritas is one of Italy’s largest multi-utility water treatment facilities, performing waste collection and treatment as well as an integrated water cycle. According to international standards, their analysis laboratory monitors the drinking water quality (78 million cubic metres distributed through their water service annually) that runs through their treatment facility. One method is to use thermogravimetric analysis on the sludge residue left over from the water treatment process.

Automating Better Water: The TGA and Water Treatment
Automating Better Water: The TGA and Water Treatment

Veritas employs three TGA701s and one TGA801 for this analysis. Each instrument can analyse up to 19 samples at the same time to determine the moisture, ash, and volatile matter of the sludge samples, which are important parameters for calculating process control metrics. This lab’s reference method for determining total solids (TS) in this sludge is: CNR IRSA 2 Q 64 Vol 2 1984 / Newsletter of Analytical Methods IRSA CNR n.2: 2008. Accredia (Accredia – L’Ente Italiano di Accredditamento – the Italian accreditation authority) has approved the adaptation of an automated method to meet the regulations.

By using automated instruments such as the TGA to handle this analysis, Veritas is able to analyze around 6,000 samples annually, improving the precision of the process. Handling errors are reduced, and the automated software controls the software to a higher accuracy than manual testing would have allowed.  Automating Better Water: The TGA and Water Treatment

Categories
Blogs

Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon Wafer Etching using Olympus LEXT OLS5100 Meta Description: Know all about the benefits of silicon wafer etching technique using Olympus LEXT OLS5100 laser confocal microscope for micro-texturing of the silicon front surface to improve the performance of solar panels, and the potential gains it can offer solar parks across India.

Silicon Wafer Etching using Olympus LEXT OLS5100

Government initiatives such as the National Solar Mission are clear indicators that the country is prioritizing meeting its energy demands through renewable sources of energy as opposed to the non-renewable counterparts. The Indian Government aims to achieve a total installed solar capacity of 20 GW by 2022. India has set up over 40 major solar plants that generate a whopping 10+ MW of solar energy to keep the nation thriving, Including the World’s Largest Solar Plant namely, Bhadla Solar Park in Rajasthan’s Jodhpur District. The increasing solar strength and opportunities in the country can be depicted by the following infographic. Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon based solar cells dominate the current photovoltaic market and are preferred by the solar cell industries. Si substrate is used as material for solar cells and microelectromechanical systems (MEMS) and integrated circuit (IC) manufacturing .Because of its environment friendliness, , paramount availability in abundance after oxygen ,high temperature, minimal price, limited current leakage, stability and also low and high power handling capacity. Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon wafer etching is a process to improve light trapping by modifying surface reflectivity of silicon wafer and use it for solar panel manufacturing. This process is called Micro-texturing of the silicon front surface. An alkaline solution is used for the etching process,which is also widely used to form micro-sized pyramidal structures on the silicon surface. Measurement of surface roughness and surface area become important parameters as they increase with increase in etching time depending on the process. So these parameters help us to understand and optimise process required to get desired etching. Silicon Wafer Etching using Olympus LEXT OLS5100

To measure height of pyramids by Conventional techniques like SEM we need to cut samples to see the cross section which makes the process tedious and is not cost effective.

To overcome this we are introducing an easy yet sophisticated solution to the aforesaid problem using Olympus OLS5100 laser Confocal Microscope. Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon Wafer Etching using Olympus LEXT OLS5100

Benefits of Using Laser Microscope for measuring the height of pyramids in textured silicon substrate during the Silicon Wafer Etching process.

Submicron Level 3D Observation & Measurement: The LEXT OLS5100 confocal laser microscope enables users to observe submicron unevenness and measure it accurately, giving the end user a closer look of the silicon wafer’s texture.

Surface Roughness Measurement: This device allows ISO compliant level measurement of the silicon wafer’s surface roughness. The user can go to arial from line profile enabling a new standard of roughness measurement.

Speedy: This is a non-contact, non-destructive technique of measurement which requires no processing. You can start to measure from the moment you put your sample under the lens.

Functional Capabilities of Laser Scanning Microscope (Silicon Wafer Etching using Olympus LEXT OLS5100)

Silicon Wafer Etching using Olympus LEXT OLS5100

Etched Silicon Wafer Image @ 2000x Zoom

Silicon Wafer Etching using Olympus LEXT OLS5100

Olympus OLS5100 captures height of individual peak using profile line and maximum peak for specific region as Sp value other important parameters to understand surface texture are surface roughness, surface area and volume of pyramid .There is need to destroy sample and it’s also non-contact so no contamination is induced during analysis. Silicon Wafer Etching using Olympus LEXT OLS5100

Measurement of Height (Silicon Wafer Etching using Olympus LEXT OLS5100)

Measurement of Volume

Olympus OLS5100 laser confocal Microscope provides us Volume and surface area for peak and valley. An ideal silicon wafer will have a homogeneous peak in height and volume and no blank zone as a valley.We can measure the volume of peaks separately to understand individual peak volume and its average so that we can optimize the etching process to achieve homogeneous peaks. Volume of the valley can also be measured as a separate value so that one can understand the process where you have a minimum black zone as a valley. White region in any laser image is a blank undesired region. Similarly, we have surface area to guide us for optimization on the etching process for desired peak and reduced blank zone as valley. Silicon Wafer Etching using Olympus LEXT OLS5100

Silicon Wafer Etching using Olympus LEXT OLS5100

Where Spd represents the density of peaks per unit area. Spc represents the arithmetic mean of principal curvature of the peak of surface.

Silicon Wafer Etching using Olympus LEXT OLS5100

Std This parameter indicates the direction angle of the texture. Therefore, we understand that pyramid like structure in given silicon wafer has angle of 99.6 deg

The PSD parameter helps us to understand the periodicity of the pyramid.

The LEXT OLS5100 Microscope’s Smart Experiment Manager.

Helps make your experiment workflow simpler by automating time-consuming tasks.

  • Automatically creates your experiment plan
  • Auto populates data to your experiment plan matrix, reducing the chance of input errors
  • Clear data trend visualization tools

Olympus OLS5100 laser confocal microscope automatically captures multiple regions on silicon wafer and helps us understand how surface area and surface roughness is changing . It eases the analysis process as it populates all data on one sheet as a head map which eliminates the need to open files individually.

Silicon Wafer Etching using Olympus LEXT OLS5100

Author- Gyanesh Singh Application Specialist at IR Technology Services Pvt. Ltd Passionate about Microscopy for Micro and Nanostructures. Gyanesh has over 10 years of experience in demonstration and serving application of various techniques to potential clients and enjoys learning new sophisticated scientific technology for Material Science and Life Science.

Categories
Blogs

How to choose the right Industrial Microscope

How to choose the right Industrial Microscope. Every business and industry has its unique requirements when it comes to microscopes. They expect high flexibility and operational readiness. An ideal microscopic solution should provide improved resolution and sample contrast. The industry demands a holistic overview of the type of sample under observation and its features like macro observation, micro observation, 3D height observation, or a combination of all. Industrial Microscopes come in many options. So, we have listed down the latest solutions available for each type of microscope to help you access what is best for your business application.

Laser Confocal Microscopes (How to choose the right Industrial Microscope)

Olympus LEXT OLS5100 combines exceptional accuracy and optical performance with smart tools that make the system easy to use. The tasks of precisely measuring shape and surface roughness at the submicron level are fast and efficient, simplifying your workflow and delivering high-quality data you can trust. It has two optical systems, color imaging and laser confocal, that enables the observer to gather information on sample color and shape in the form of high-definition images. The color imaging optics acquires information using a white-light LED light source and a CMOS image sensor while the laser confocal optics acquire confocal images using a 405 nm laser diode light source and a high-sensitivity photomultiplier. 

The shallow depth of focus enables it to measure the surface irregularities of the sample. The Olympus LEXT OLS5100 is an exceptional laser confocal device that uses a non-destructive observation method. It does not require any sample preparation— all you need to do is place the sample on the stage and it’s ready to measure. Ready to measure. (How to choose the right Industrial Microscope)

Digital Microscopes

The DSX1000 Digital Microscope is the first of its kind with the possibility of observing macro, micro, and 3D features of a sample from 20x to 7000x magnification. It comes with 17 objective lenses, including super long working distance and high numerical aperture options, which provide the flexibility to obtain a wide range of images. The eucentric optical design maintains a good visual field when tilted or when the stage is rotated, enabling you to observe your sample from all possible angles. It displays sample images captured with 6 different observation methods with a single click. Olympus DSX 1000 is an ideal solution for Education, research, forensics, electronics, quality control, metal fabrication, automotive, etc. Packed with a telecentric optical system the DSX1000 guarantees accuracy and repeatability.

Stereo Zoom Microscope (How to choose the right Industrial Microscope)

How to choose the right Industrial Microscope

This type of microscope is ideal for viewing large specimens. Stereo Zoom Microscopes provide the observer with an upright view of the subject as a stereoscopic 3D picture versus a 2D flat image view by compound microscope. They are the choice of microscope for applications such as circuit board repair, circuit board inspection, surface mount technology work, electronics inspection, coin collecting, gemology and gemstone setting, engraving, repair & inspection of small parts, and detecting manufacturing or production flaws in quality control units of various industries. Olympus SZ61/SZ51 is a reliable stereo zoom microscope if you are looking for consistently accurate results from your observations. (How to choose the right Industrial Microscope)

Light Microscope

If your study involves observing fine objects in great detail, a light microscope might just be the tool for you. Light microscopes aided by visible light can detect, magnify and enlarge your specimen to fit your observation needs. They use a series of glass lenses to aim a light beam through the subject and then through convex objective lenses to produce an enlarged view. Olympus Light Microscopes are available in the Upright, Inverted, and Modular version, and are ideal for integration with advanced inspection systems providing versatility for a variety of materials science and industrial applications. (How to choose the right Industrial Microscope)

Measuring Microscope (How to choose the right Industrial Microscope)

How to choose the right Industrial Microscope

Industrial measuring microscopes combine sophisticated optics with a table that enables precise movements to measure targets. Their functional diversity allows them to meet high precision inspection needs. So if you are looking to gather high-performance readings of complex samples, choose a measuring microscope. They provide reliable, accurate, and repeatable measurements on the three axes. Therefore their primary applications include quality control and assembly. Check out the Olympus STM7 for versatility in application and high performance. It is a user-friendly device with high-precision and allows 3-Axis Measurement.

Semiconductor & Flat Panel Display Inspection Microscopes

As the name describes Semiconductor & Flat Panel Display Inspection Microscopes provide high-quality observations for large-sized samples, up to 300 mm wafers, flat panel displays, printed circuit boards, etc. Olympus MX63/MX63L and AL120 are the industry-leading models for these inspection microscopes. (How to choose the right Industrial Microscope)

Cleanliness Inspector (How to choose the right Industrial Microscope)

How to choose the right Industrial Microscope

The practical application of particle size and distribution can directly impact the efficiency, lifespan, and dependability of many manufactured products. Therefore, it is essential to have a reliable solution for particle counting, sizing, and classification. Olympus CIX100 is the most sought after inspection system for manufacturers who maintain high standards for cleanliness of the components they manufacture. It can acquire, process, and document technical cleanliness inspection data in a matter of a few minutes. It has an intuitive software which guides the users step by step through the process, enabling novice operators to acquire cleanliness data with ease.

Industrial microscopes have various applications in major industries like electronics, metals, academic research, glass and ceramics, environment, mining, geology, and others. So it is important to map the functionality of each type to the requirements of your applications. Similar to any industry, the key to making the right decision with microscopy is having the right device for the task at hand. Consider, what you want to observe, what is the nature of your subject, does the subject allow light to pass through and the objective of the observation. This will help you narrow down your search from Industrial Microscopes to Compound/Stereo microscope and further into any type of niche microscopy.

Author- Gyanesh Singh Application Specialist at IR Technology Services Pvt. Ltd Passionate about Microscopy for Micro and Nanostructures. Gyanesh has over 10 years of experience in demonstration and serving application of various techniques to potential clients and enjoys learning new sophisticated scientific technology for Material Science and Life Science.

Categories
Blogs

Surface Roughness Observation of a Diamond

Surface Roughness Observation of a Diamond with Olympus DSX1000 & OLS5100 Microscopes

Surface Roughness Observation of a Diamonds. Diamonds are among nature’s most precious and beautiful creations. Diamond is much more than the world’s most popular gemstone and the most rigid natural material. But with the glamour comes a few flaws that might result in losing its shine. To maintain the standard quality, it becomes essential to understand the properties, defects and learn about the highly advanced technological solutions to measure them.

Diamond is a solid form of carbon with its atoms arranged in a crystal structure called diamond cubic. At room temperature and pressure, another solid form of carbon known as graphite is the chemically stable carbon form, but diamond seldom converts.

It has the highest hardness and thermal conductivity of any natural material, properties utilized in major industrial applications such as cutting and polishing tools. Rough diamonds are mined and converted into gems through a multi-step process known as “cutting”. Diamonds are rigid but also brittle and can be split up by a single blow. Therefore, diamond cutting is traditionally considered a delicate procedure requiring skills, scientific knowledge, tools and experience. Its final goal is to produce a faceted jewel where the specific angles between the facets would optimize the diamond luster, that is, dispersion of white light. In contrast, the number and area of facets would determine the weight of the final product. (Surface Roughness Observation of a Diamond)

(Surface Roughness Observation of a Diamond)Some of them may be considered classical, such as round, pear, marquise, oval, hearts and arrows, diamonds, etc. The diamond price depends on cut, color, clarity, and karat. There are certain American certification agencies where the quality of the diamond is certified.

The imperfections in diamonds can be classified as External and Internal Flaw, which can be explained as follows:(Surface Roughness Observation of a Diamond)Some of them may be considered classical, such as round, pear, marquise, oval, hearts and arrows, diamonds, etc. The diamond price depends on cut, color, clarity, and karat. There are certain American certification agencies where the quality of the diamond is certified. The imperfections in diamonds can be classified as External and Internal Flaw, which can be explained as follows:

External Flaws:

  • Blemishes: These diamond flaws are present on the surface of a stone and can occur naturally
  • Scratches: These are fine lines found on the surface of the diamond. They may have been present naturally or caused when a diamond was cut.
  • Extra facets: These are usually cut to remove blemishes or undoubtedly close to surface inclusions on diamonds. At times these different facets are also cut to enhance the brilliance of the diamond.
  • Fracture: A breakage in diamonds that is not parallel to the cleavage plane is a fracture. Fractures are usually irregular in shape, making a diamond look chipped (Surface Roughness Observation of a Diamond).
  • Fingerprints: Fingerprint inclusions in the shape of fingerprints can sometimes be found in diamonds. However, such inclusions are rare in diamonds as compared to other stones, such as rubies.
  • Pits: Small holes may be present on the surface of a diamond. These pits are usually not visible to the naked eye.
  • Nicks: Diamonds are also chipped at places, causing the appearance of nicks. It is often repaired by adding extra facets.

Internal Flaws:

  • Crystal/mineral inclusions: Some diamonds show the presence of tiny crystals, minerals or other diamonds.
  • Pinpoint inclusions: As the name implies, these inclusions are minute crystals, usually white, present inside the diamond.
  • Needles: Diamond crystals in a diamond can also be present in the form of long and thin needles. These may not be visible to the naked eye. (Surface Roughness Observation of a Diamond)
  • Cloud: The presence of three or more pinpoint inclusions close together can create a haze area, or a cloud, in the diamond.
  • Knots: When diamond crystals extend to the surface of the diamond, they are referred to as knots. These can be viewed under proper lighting conditions with a diamond loupe.
  • Graining: Crystal inclusions in diamonds occur in the form of lines known as graining. Graining should not be confused with rough diamonds natural grain lines.

Hence to determine the defects and attain superior quality control, we can switch to technologically advanced solutions like The Olympus DSX1000 & The Laser Microscope OLS5100, which have proven excellent performance. For a better understanding, let’s study some of the results obtained through this equipment. (Surface Roughness Observation of a Diamond)

Ø  The Olympus DSX1000 Microscope captures such flows from BF observation, Oblique mode, DIC with contrast enhancement. The below images represent snaps of diamond in different image types like Colour Snap, Extended Height.

Surface Roughness Observation of a Diamond

IMAGE FROM MICROSCOPE

Surface Roughness Observation of a Diamond
Surface Roughness Observation of a Diamond

The below images show the SCRATCHES on the surface of diamond with different observation modes like OBQ and DIC at other objectives.

1. BF + contrast with SXLOB3X Objective

Surface Roughness Observation of a Diamond

2. DIC Observation with SXLOB3X Objective

3. OBQ Observation with SXLOB3X Objective

4. DIC Observation with SXLOB3X Objective

Surface Roughness Observation of a Diamond

5. DIC Observation with APO50x Objective

Surface Roughness Observation of a Diamond

6. The flat surface in DIC (Surface Roughness Observation of a Diamond)

Surface Roughness Observation of a Diamond

7. Mag-1750X, DIC Observation with APO50X Objective

Surface Roughness Observation of a Diamond

All other kinds of internal or external flaws like inclusion, fracture, pits, etc. can be explored using polarised light.

Ø  The Laser OLS5100 Microscope offers a 1750X view which allows us to see deformations as a scratch on the surface of the diamond. To find the roughness information for such surface areas in Nanometer, we will have to use the OLS5100 laser microscope, which employs a 405 nm laser source to scan the sample using confocal technique and capture height resolution 6nm.

1. At 2500 x magnification (Surface Roughness Observation of a Diamond)

2. Result View: For example, from the below report, it can be concluded that the Roughness value Ra is 20nm. The maximum peak observed is Rp 58 nm, and the maximum valley followed is Rv 49 nm.

Thus, choosing the right analytical method and tool helps in identification of and defects and accurate measurements to exercise precise quality control. (Surface Roughness Observation of a Diamond)

Author- Gyanesh Singh Application Specialist at IR Technology Services Pvt. Ltd Passionate about Microscopy for Micro and Nanostructures. Gyanesh has over 10 years of experience in demonstration and serving application of various techniques to potential clients and enjoys learning new sophisticated scientific technology for Material Science and Life Science.

×