and allowing for all steps to be performed in the same vessel affords quite an improvement.

Transcription

1 Chemicals Analytical solutions in the laboratory 12 News Edition No. 1 / February 2013 Automate and Simplify Hydroxyl Group Determination The hydroxyl group is an important and functional group of organic compounds used in the production of intermediate and finished products, such as polyols, resins and lubricants. Titration Excellence is the perfect solution for the important, yet challenging, determination of hydroxyl content with fully automated sample and reagent handling. A number of methods are recognized for hydroxyl content determination with the majority involving titration. Traditional determination uses the acetylation of the OH (hydroxyl) groups with an excess of acetic anhydride in pyridine while boiled under reflux. The excess acetic anhydride is hydrolyzed to acetic acid and titrated with a base, typically KOH (potassium hydroxide) in methanol to determine the OH content. Although a simple chemistry, this method is prone to multiple errors when transferring the solution into and out of the reflux apparatus. The multiple steps make complete automation impossible as well as time consuming and hazardous due to the presence of pyridine. In most cases, the acetylation mechanism can be followed using a catalyst instead of pyridine and heat. Typical catalysts are N- methylimidazole and 4-N-dimethylaminopyridine, which are less carcinogenic than the pyridine and have a significantly less unpleasant odour. Lowering the reaction time to 15 minutes at room temperature and allowing for all steps to be performed in the same vessel affords quite an improvement. Fully automated solution Even after removing the pyridine, refluxing and a long acetylation time, a complex procedure remains. It is sensitive to water influx, requires extensive chemical handling and close attention to mixing times in order to keep up with production. Multiple blank titrations are also

2 Tips & Tricks Titration See how solvent manager helps to limit chemical contact Limit your operators contact with hazardous chemicals and waste with METTLER TOLEDO's Solvent Manager. T90 Excellence Titrator with the Rondo20 sample changer offers complete automated soluton for up to 20 samples. necessary to accurately account for the volume and strength of the acetic anhydride. Up to 20 samples can be automatically determined for acid (if necessary) and hydroxyl values with the METTLER TOLEDO T90 Excellence Titrator when used in conjunction with the Rondo20 sample changer. The key features and advantages of using this system are: Burettes for accurate and repeatable acetic anhydride dosing. One Click user interface for easy operation, including automatic reagent flushing and blank determinations. Rondo CoverUp TM protects the samples from water ingress as they wait to be titrated. Utilizing the Rondo PowerShower to clean the electrode, stirrer and tubes ensures no sample or excess titrant cross contamination. Two towers on the Rondo20 separate reaction and titration components and reagents. Optional heating with the DH100 to speed up the reaction time and increase solubility. Titration of both acid and hydroxyl content on 2 samples with integrated results. T90 conditional logic with if-then actions for out of spec samples or standards. LevelSens prevents running out of reagents and waste overflow during analysis. The T90 Rondo20 system offers several possibilities for archiving and exporting data using a USB printer, memory stick, direct export of xml files and LabX titration software. LabX software offers unique data capture, networking and the automated export of results to a LIMS or ERP system. The combination of a T90, Rondo20, LabX titration software and the tailored accessories from METTLER TOLEDO, ensures accurate, repeatable, fully automated, simple and secure hydroxyl value content. Watch the demonstration video to see how the Solvent Manager can make your lab safer. SolventManager Publisher Mettler-Toledo AG Laboratory Division Im Langacher CH-8606 Greifensee, Switzerland Production LAB Division Marketing Global MarCom Switzerland Text: Giorgio Gallimberti, Lab Area Manager, METTLER TOLEDO Italy Subject to technical changes. Mettler-Toledo AG 02/13 Printed in Switzerland. 2

3 Chemical Synthesis Beyond the Round Bottom Flask Researchers in synthetic organic chemistry are under increasing pressure to discover and develop new and improved chemical reactions and processes as quickly as possible. While analytical technologies have changed dramatically, chemical synthesis itself has remained largely unchanged for over fifty years. A new type of approach is now helping chemists to redefine the way that chemical syntheses are researched and performed. Know-how Learn more insight about chemical synthesis A white paper is now available that discusses how newly developed methodologies for chemical synthesis are eliminating key challenges and introduces the concept of chemical synthesis without the traditional round bottom flask. New experimental techniques for organic synthesis. Download here: organicsynthesis Historically, the round bottom flask has been the work-horse in the synthesis lab but it has its drawbacks. Heating and cooling of the reaction mass is difficult and imprecise and maintaining temperature over several hours is challenging. In many cases, synthesis steps are impossible to perform unless a scientist is present to supervise the reaction and repeating a synthesis is not always straightforward. A new technology has been developed that helps scientists develop a greater understanding of the reactions they study and has redefined the way organic syntheses are researched and performed while maintaining their current workflow. Replacing the round bottom flask EasyMax and OptiMax synthesis work stations eliminate the need to use heating mantles, oil and ice baths and cryostats. With no training requirement, EasyMax is fast and easy to set-up making users immediately productive. The touchscreen is used to change conditions and program a few steps ahead. Reactions can be run safely unattended day or night and the workstation captures experimental data to deliver an enhanced understanding of the reaction under investigation leading to faster reaction optimization. Every reaction event is captured and experiments are easily compared and repeated. Text: Urs Groth, Head of Communications Reaction Engineering EasyMax 3

4 Bottling & Filling of Peptides Enhanced Bottling Process Boosts Productivity The logistics group of a leading Swiss biochemical company has the task of managing the supply of peptides and proteins from the 4,400 bio chemicals in their catalogue. These chemical substances can be expensive as they require multi-step syntheses and are generally sold in small quantities, ranging from 1 to several hundred milligrams. Installing the Quantos automatic dosing system for bottling these samples has greatly enhanced productivity in the group and realized substantial savings for the company. The peptide and protein samples, of fixed target weight, are typically dosed manually using a spatula from a single source container into individual bottles. Dosing such small quantities takes a lab technician 2 to 3 minutes per sample. Usually, 30 to 100 units are filled from one production batch, but this can also be as many as 1000 a tedious and tiring task for the operator. Time consuming manual weighing When working on this task for up to 5 hours per day, operators may suffer loss of concentration, leading to errors and outof-specification samples. It is also critical that the sample bottle is not under filled, i.e. it must not contain less than the amount stated on the label. EU regulation 76/211/EWG for filling states that, "The actual mass of the contents of a flask can vary to maximum 9% compared to the written label." Quantos QB5 automated dosing system with auto sampler. The pressure was on for this company to enhance productivity and speed up the filling process in order to meet customer demand. The company was also keen to 4

5 Know-how Learn more about automated solution for bottling & filling of chemicals in small quantity Automated bottling and labelling enhances process and data security. reduce the costs incurred due to overfilling as they were effectively giving away a proportion of the samples for free. Fast dosing process with automated solution The perfect solution to their bottling bottleneck was the Quantos automated dosing system in combination with a 30-position auto sampler. Once the substance was loaded into a dosing head, 30 target containers could be dosed without user intervention, each with varying target weights if required. On average, filling each sample container takes just seconds four times faster than manual filling. Automatically generated labels simplify the logistical track that the samples take and enhance data security. A range of adapters are available to accommodate different sizes of target bottle which also serve to reduce electrostatic effects. Return-on-investment in less than 1 year Two Quantos systems were installed at this site 3 years ago and the customer is delighted with the performance for filling and bottling applications, as well as the impact these automated systems have had on productivity and savings. Productivity at this site has increased more than 4 fold and significant savings were made by dosing to an accuracy of 2% of the desired sample weight, as opposed to overfilling by 9%. They have determined that the system has paid for itself in less than 10 months! Net investment costs = 49, Annual cost of consumables = 2, Total costs in the first year = 51, Total annual gross savings = 62, Net savings in 5 years = 252, Quantos technology can be applied to any bottlers and distributors of fine chemicals, reference materials and standards dispensing substances in the range 1 mg to several grams interested in enhancing productivity and saving money on costly and the unnecessary overfilling of samples. Text: Joanne Ratcliff, Product Manager In the current global climate, all companies and industries are looking for ways to increase their productivity and reduce their costs. For manufacturers and distributors of fine chemicals, reference materials and standards and particularly those who are concerned with bottling, filling and repackaging of small quantities of chemicals (e.g. 1mg to several grams), there is an automated powder dosing solution that will revolutionize your processes. Join the webinar: 5

6 Material Characterization Investigating Cobalt Chloride Simultaneously and Video-Recorded Cobalt chloride is a blue, hygroscopic substance that turns red when it absorbs moisture. The characteristic color change makes it very useful as a moisture indicator for drying agents, such as silica gel. Investigation of the drying behavior of cobalt chloride hexahydrate excellently demonstrates how DSC microscopy helps the interpretation of results. DSC 1 Cobalt chloride, or more precisely cobalt chloride hexahydrate (CoCl2 6H2O), is a ruby red, poisonous salt. It is strongly hygroscopic and is often used as a drying agent. For this application, silica gel is usually impregnated with cobalt chloride, which gives it a blue color when it is dry. If the impregnated silica gel absorbs moisture, it becomes red. This is due to the fact that anhydrous cobalt chloride absorbs water and forms the ruby-red cobalt chloride hexahydrate. The silica gel can be regenerated by heating to around 160 C in order to remove any water. Experimental details The DSC experiments were performed in a static air atmosphere using a DSC 1 equipped with an FRS5 sensor and the microscopy accessory. Results Figure 1 shows several images recorded while the sample was heated. The area of the image shown here is actually about 1.5 x 2.3 mm. The sample initially has the characteristic red color of cobalt chloride hexahydrate. It gradually becomes lighter in color until the color suddenly changes at about 53 C. Further color changes are detected at higher temperatures: between 100 and 120 C, the color changes from lilac to blue and at 160 C the sample is pale blue. These color differences can be quantified by calculating an average brightness for each image. The results are then displayed as a curve showing the average image brightness as a function of temperature. Figure 2 shows a typical brightness curve together with the DSC measurement curve. The numbers correspond to the images in Figure 1. The DSC curve (blue curve in Figure 2) shows a broad endothermic peak up to about 80 C on which a sharp peak is superimposed with an onset at 53 C. Two further endothermic peaks are visible that begin at about 104 C and 130 C respectively. The brightness of the images (red curve in Figure 2) increases slowly initially, but suddenly decreases at about 53 C. It then increases again in several steps. Clearly, the two curves involve the same physicalchemical effects. The sample loses water right from the beginning of the measurement; the evaporation rate increases with rising temperature (the curve becomes 6

7 Figure 1. Images of cobalt chloride crystals in 30μL alumina crucibles at different temperatures. Figure 2. The DSC curve and the average image brightness of cobalt chloride hexahydrate as a function of temperature. more and more endothermic). At about 53 C, the material changes its crystalline structure. This causes the marked color change and the sharp endothermic peak in the DSC curve. Closer examination of the sample images at around 53 C reveals small droplets of water on the surface of the crystals. This indicates that at least part of the remaining water of crystallization was eliminated from the crystal lattice to the surface of the crystals during the solid-solid transition. The color changes continuously as the crystallites dry. This process is completed by about 80 C. The two, step-like changes in the brightness and the two broad endothermic peaks on the DSC curve also result from the release of water of crystallization. The interpretation of the DSC measurements was confirmed by TGA measurements. Conclusions DSC microscopy allows images of a sample to be recorded by a camera while the sample is measured in the DSC 1. Visual changes can be documented and correlated with effects on the DSC curve. DSC microscopy can detect color changes as a result of chemical reactions (decomposition) or polymorphism and changes in the 'morphology' of samples, e.g. as a result of melting or flowing, shrinkage or expansion, movement of the sample during glass transitions, solid-solid transitions or the formation of cracks. Text: Dr. Matthias Wagner, Product Manager Materials Characterization; Dr. Markus Schubnell, Application Physicist Practical tip Aluminum crucibles are not suitable for DSC microscopy because their upper surface reflects light very strongly. We often use the 30-μL alumina crucible or a 40-μL aluminum crucible in which we place a gold-plated aluminum disk as the background. These disks are used as seals in high-pressure crucibles and can be ordered separately. The measurements described here on cobalt chloride were performed using 30-μL alumina crucibles. 7

8 Good Measuring Practices Good Measuring Practices Reliability Throughout the Lifecycle Good Measuring Practices by METTLER TOLEDO is a global program supporting you in laboratory and production environments with quality assurance recommendations for weighing, pipetting and chemical analysis. The five steps of every Good Measuring Practices guideline cover the entire lifecycle of your instruments. By focusing on your processes and its associated requirements and risks, we provide you with effective measures to maximize operational security and minimize testing efforts and process risk. GWP Good Weighing Practice GTP Good Titration Practice GPP Good Pipetting Practice Guaranteed better weighing results GWP helps ensuring consistent product quality and avoiding outof-spec results or bad production batches. With GWP you comply with all regulations relevant to your industry for a minimal time and financial investment. GWP provides documentation to verify the accuracy of your balances and recommends optimal testing procedures. Reliable results and dependable titration in practice GTP forms the basis of dependable and risk-free titration. The appropriate titration system is selected based on user requirements, and professionally commissioned and installed. GTP helps protecting your investment far into the future, supporting you with tailored training and equipment qualification. It also proposes schedules for regular inspection and preventive maintenance. Optimize workflows for more reliable and repeatable results Improve your data quality with GPP our comprehensive, systematic approach to maximizing pipetting accuracy and repeatability. GPP is grounded in 40+ years of expertise working side-by-side with researchers in order to achieve the highest level of accuracy and precision across all applications

9 GDRP Good Density and Refractometry Practice GEP Good Electrochemistry Practice Minimize risk and improve performance GDRP is based on our expertise in density and refractive index measurement. Understanding the reasons and sources of measurement errors helps improving quality while reducing risks and costs. Professional commissioning, training, qualification and seamless documentation guarantee compliance with your process requirements from the very first step. Optimized ph results from the beginning GEP assists with professional tools and documentation to get reliable results for your laboratory ph, conductivity, DO, ion and redox applications. Use GEP to select the correct calibration solutions to comply with regulations, perfectly maintain your sensors to optimize product lifespan and reduce costly measurement mistakes to a minimum. Check your risks in weighing, titration and chemical analysis Risk Check All of the Good Measuring Practices guidelines start with an evaluation of your measurement processes and an assessment of their associated risks. Based on this information, you are provided with straightforward recommendations for selecting, installing, calibrating and operating your devices. For more Information: Good Measuring Practices 9

10 Product Highlight Better Understanding of Particles Fast, Confident Process Optimization Scientists and engineers use Focused Beam Reflectance Measurement (FBRM ) to track particles and droplets as they naturally exist in process. The new generation of FBRM (the G Series) simplifies these tasks even further. By improving chord length accuracy, correcting for stuck particles and increasing dynamic range, the next generation FBRM provides more intuitive information while tracking critical product parameters with both higher precision and improved accuracy. Ergonomical Lightweight, stackable control boxes can be installed inside the fume-hood or on the lab bench eliminating the need for a cart. A new ergonomic probeconduit design simplifies reactor integration and ease of use. Interchangeable Quickly switch between interchangeable 9.5 mm and 14 mm FBRM probes for versatility across a wide range of experimental volumes, thus lowering the capital investment for a complete lab setup. Robust The fully redesigned G400 is manufactured with a reinforced 9.5 mm probe tube for a quick setup and robust, dependable in-process particle measurement. 10

11 Balance Protection for Safe and Clean Operation Laboratory balances are frequently exposed to aggressive chemicals, such as strong acids, bases or organic solvents. Sulfuric acid, hydrochloric acid and aqua regia are just some of the corrosive substances used daily in many chemical, analytical and biochemical labs. Even when not in use, dust and dirt accumulate on the balance. Protect Excellence Balances against daily lab hazards and protect your investment. Always Protected Use a dust cover to keep dust and dirt at bay while balances are not in use. Covers available for all Excellence Micro, Analytical and small platform Precision Balances. Damage Avoidance Platform covers for precision balances avoid any potential damage to the weighing platform. No more worries about difficult to clean samples; just lift off and replace when soiled. Visible Contamination The grey drip tray for analytical balances makes it easier to see any spilled samples. The tray simply lifts out for cleaning and cross-contamination is avoided. It s dishwasher safe too. Disposable Protection This cover protects the balance terminal from dirt and hazardous or sticky samples without interfering with balance operation. Simply dispose of and replace to eliminate crosscontamination. 11

12 Everything in Our Lab Works With Just One Click Joanne, laboratory assistant: "Thanks to my personalized Homescreen, I can perform all the different analyses very quickly and efficiently." Bob, production assistant: "All I have to do to analyze the intermediate product every hour is press a Shortcut." Clark, quality assurance: "The individual user rights feature means that I can make sure that users stick to our quality guidelines." The One Click operation provides unsurpassed user guidance, secure navigation and easily selectable and adaptable methods. Learn more and see One Click in action: Key benefits of One Click operation: Know one know all One Click is a common interface for all your lab instruments. This means, if you can program and run analyses on a balance, you can also do it on a titrator, without extra information required. See only what is relevant to you User screen individualization permits you to adapt your home screen to your requirements: You only see what you need and avoid confusion by unneeded functionalities. Play by the rules Adherence to SOPs is now a functionality of your instrument via the pre-programming of methods. Transcription and calculation errors a thing of the past. Mettler-Toledo AG Laboratory Division Im Langacher CH-8606 Greifensee, Switzerland For more information