26
Analytical Instrumentation A Solution to an Old Titration Problem
There are various designs of titration vessels used on coulometric Karl Fischer titrators and they all have one thing in common, the interior of the titration vessel should be sealed from ingress of atmospheric moisture.
To achieve this, the most frequently used design is to have ground glass joints on the generator and detector electrodes which are then fitted into ground glass joints on the lid of the titration vessel. However it is well known that dry ground glass joints will have a tendency to stick to each other and then the problems begin.
The most expensive part of any coulometric Karl Fischer instrument is generally the glassware, especially the titration vessel and electrodes. If these become stuck then it can be a very costly exercise trying to separate them, often resulting in breakages.
To overcome this problem many manufacturers suggest smearing grease on the electrode joints or, alternatively, fit Teflon sleeves over the joints. Each of these methods are equally effective but they are also equally problematic. If grease is being used to seal the electrodes into place then it is necessary to turn the joint at least once per week to ensure that the grease has not dried out and the electrode stuck. This precaution is usually stated clearly in the user manual. Similarly, when the glassware is periodically cleaned and recharged with fresh reagents the teflon sleeve should also be cleaned, dried and refitted to the electrode joint. These sleeves are often lost or damaged which once again leads to electrodes being stuck in the titration vessel.
Originally designed for coulometer users on North Sea oil and gas platforms, G.R. Scientific’s (UK) Low Drift Cell uses a special design of glass joint which will not stick or jam and is totally grease free. The connecting cap of the electrode is screwed down to compress the O-ring on to the top of the female joint which is part of the titration vessel, ensuring a perfect seal. To release the electrode simply unscrew the connecting cap and the loosening ring will lift the electrode free from the joint. Hassle free assembly and disassembly is guaranteed.
Reader Reply Card No Activa S ICP-OES Spectrometer: Designed for Organic Samples Analysis
Horiba Scientific ACTIVA S ICP-OES is the perfect instrument to perform organic samples analysis thanks to its Simplicity and its Stability. The vertical torch and the radial viewing mode associated with the unique total plasma view allow achieving really low detection limits and excellent stability, providing high performance for laboratories. For Biofuels, compliance with US and EU specifications such as ASTM D6751, EN14214 and DIN 51606 is possible as shown in the Application Flash "Biodiesel". The analysis of wear metals in oils following the recommendations of ASTM D5185 is also possible. Perfect accuracy and stability is offered by the ACTIVA S as shown in the Application Note "Wear metals and additive elements analysis in used lubricating oils". To receive these application notes please contact us at
info.sci@
horiba.com or go to
www.horiba.com/scientific/activaS
Reader Reply Card No
New GC Method Translator Speeds Development of Fast GC Methods
The Envantage (USA) Method Translator is a new tool to speed up GC methods using the equation of Golay (the inventor of capillary GC). The EMT is tailored for split/splitless injection on an open end capillary column. Pneumatics are assessed with Hagen-Poiseuille pipe flow and the Halasz gas compressibility correction. Isothermal optimum conditions on smaller columns are obtained with the Enskog and Chapman carrier gas diffusion and a constant liquid diffusion. Pressure drop, typical for fast GC, is accounted for by average column pressure diffusion, which follows from the James and Martin relation. The isothermal resolution gain, speed gain and sensitivity loss apply to temperature programmed gas chromatography as well.
Reader Reply Card No New Rotary Valve Concept
Analytical Flow Products (Canada) have announced that two new Chinese patents have been recently granted. One of these patents is for their new rotary valve concept with purging grooves design. The other one is for the tight shut off concept of their diaphragm base valves. Refer to Chinese patent CN 101163912 B and CN 101011346 B; both valves series are already in production.
The DV series diaphragm valves are highly popular in sample stream selection, and will have their electrical version ready in January 2011. This eliminates the need to have actuating gas.
In January 2011, a high temperature version of their pneumatic G.C. rotary valve actuator will be released. It can be used directly in an oven up to 300°C, eliminating the need for the traditional standoff. In addition, most of their products literatures are now available in Chinese. Three new distributors have been appointed; Hardee Sales for Louisiana, Mississippi, Alabama and Houston area and Can Flow Technology Inc for the Canadian Market and EIF Filtres for France Market.
Their analytical and sample stream selection valves are now available for the NeSSI™ platform, as per ANSI/ISA- 76.00.02-2002 standard.
Reader Reply Card No 75 Reader Reply Card No
Reversible Inlet Seal-Same Cost, Twice the Lifetime
Ring Inlet Seals, meaning no extra washer is needed. Flip Seal™ inlet seals have a lower leak rate than OEM metal seals, and the highly inert gold plated or Siltek® treated surface helps maximise transfer of analytes to column.
New reversible Flip Seal™ inlet seals from Restek (USA) last twice as long as other inlet seals. Simply use—flip—then use again. The reversible design doubles the number of analyses you get per seal. These inlet seals use the same easy sealing mechanism as Dual Vespel®
Reader Reply Card No 76 Reader Reply Card No 77 74 73 72 71
Annual Buyers’ Guide 2011
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108
