The Impact of Spare Parts. Performance

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1 The Impact of Spare Parts Design and Manufacturing on ACQUITY UPLC System Performance High quality spare parts ensure that your ACQUITY UPLC System runs optimally, protecting your investment in state-of-the-art technology.

2 Executive Summary Waters introduced the ACQUITY UPLC System in 2004 in response to customers need for new levels of efficiency and accuracy from analytical instruments. This ground-breaking technology has enabled many laboratories to increase productivity 1 and lower analysis costs 2 by reducing sample runtimes and lowering solvent/sample consumption. The ACQUITY UPLC System s holistic design is based on a patented sub-2-μm hybrid particle chemistry, which allows chromatographers to work at higher efficiencies with a much wider range of linear velocities, flow rates, and backpressures. 3 Every aspect of parts design, manufacture and packaging was re-engineered and optimized during ACQUITY UPLC System development to ensure optimal long-term performance. In recent times, certain vendors have promoted the use of non- Waters parts on ACQUITY UPLC Systems. Test results on these parts reveal many significant differences that will seriously compromise ACQUITY UPLC System performance. Examples include: Scratches on sealing surfaces Issues with the flatness of sealing surfaces Material inconsistencies Different material compositions Contamination on parts The impacts of these non-conformances include: Increased downtime due to part or instrument failures System compliance testing failures System contamination System carryover Inaccurate results Patented UPLC Solvent Delivery System With the introduction of ACQUITY UPLC Systems, Waters introduced new sample managers, new solvent managers, several detectors and the Waters Critical Clean process for ACQUITY UPLC System fluidic components. These precision components were all designed to interact holistically at the elevated pressures utilized with Ultra Performance Liquid Chromatography. In comparison to HPLC operating pressures which typically go up to 3,000 psi, these higher pressures required significant advances in how solvent was delivered thus Waters patented its new solvent delivery design (U.S. Patent No, 7,665,480). With higher pressures, there is a greater risk that components will fail, in particular any seals in the fluid path. To ensure that Waters parts do not fail prematurely, all of the system components are manufactured with critically controlled tolerances. UPLC Inject Valve and Vent Valve In order to keep the UPLC solvent delivery system working at its optimum performance, there are some assemblies, such as, the sample manager s inject valve and the solvent manager s vent valve that Waters does not recommend rebuilding in the laboratory. These assemblies are manufactured with strict quality control processes and with specialized tooling to preload the internal components so that they can withstand the high pressures of UPLC. That is why Waters does not sell the rotors and stators for these valves individually. Without the proper tools, disassembly and reassembly of an inject valve or vent valve in a laboratory will result in premature failure of components due to the lack of compression between the rotor and stator. Some vendors do sell rotors and stators individually claiming these parts are equivalent to Waters components, but inspection tests on these third-party parts reveal several critical differences in the quality of those parts. Using these non-waters parts will significantly decrease the life cycle of a Waters inject or vent valve. 2

3 Rotors Inspection of a third-party rotor to a Waters rotor revealed several significant design differences: Flatness issues in the critical sealing areas Closer inspection of the surface of the third-party rotor in Figure 3 reveals an indentation in the middle of the rotor a critical sealing area. This indentation would definitely affect the sealing of the rotor to a stator. Voids and scratches in the critical sealing area Fractures in the carbon fiber Part not within Waters flatness specification Part not within Waters parallelism specification The following images were obtained using a white light interferometer. Figures 1 and 2 reveal the overall flatness of the rotor surface. The Waters rotor (Figure 2) shows a consistent flat surface, whereas the third-party rotor (Figure 1) shows serious flatness issues and does not meet the specifications required to seal properly under high pressures. Figure 3. Indentation in third-party rotor. Figure 4. Waters inject valve rotor. Figure 1. Third-party rotor. Photomicrographs also revealed a fracture (Figure 5), along with scratches and flecks on the surface (Figure 6) which indicate an inconsistent lay to the rotor material in the third-party parts. Figure 7 shows the Waters rotor material is very consistent and free of scratches. Figure 2. Waters inject valve rotor. Figure 5. Fracture in third-party rotor. Figure 6. Scratches and surface flecks in third-party rotor. Figure 7. Waters rotor surface. 3

4 Backup Washer Another fluid component inspected was the high pressure backup washer. This part was inspected using a scanning electron microscope. Notice in Figure 8, the grooves in the third-party washer are wide and not cleanly cut and the center hole is extremely jagged. This could compromise the effectiveness of this component. Compare this to the Waters backup washer in Figure 9. The surface and edges are smooth and the channels are clean cut and narrow. Figure 10. Third-party seal. Figure 8. Third-party backup washer. Figure 11. Waters seal. Seal Figure 9. Waters backup washer. Seal performance can have a profound impact on instrument performance. The performance of the seal is governed to a great extent by the finish of the mating surface over which the seal slides. Waters has established proprietary polymer blends designed to enhance seal life while reducing the occurrence of contamination due to seal shredding. Using a scanning electron microscope to examine a third-party seal and a Waters seal reveals some major differences in the sealing surfaces. Notice the ragged surface on the third-party seal (Figure 10) when compared to the smoothness of the Waters seal (Figure 11). The third-party seal would have problems sealing properly over time and would not have the same longevity that a Waters seal has. A big concern seen with the third-party seal is the overall cleanliness of the part. Particles can be seen on the spring in Figure 10. Particles from the rough seal surface will likely shred and cause a blockage of the binary solvent manager s filter frit. If the particles enter the pump head, this will accelerate the wear on the seal and result in premature failure or leaking. With the Waters Critical Clean process, the ACQUITY UPLC System fluidic components are manufactured and handled in a controlled process to minimize any organic or inorganic particulate contamination. Seal Springs Maintaining a constant spring force is also important to seal performance. Waters seals use loaded springs specifically designed for the tolerances established for the instrument. This ensures that Waters seals will maintain a near constant spring force from start to finish, resulting in a better seal and, ultimately, more consistent results. If you compare the springs in Figures 10 and 11, notice the difference in the density and spacing of the spring coils. The third-party seal springs are not spaced the same as the Waters seal springs. 4

5 % Composition Element 1 Element 2 Element 3 Element 4 Element 5 Element 6 Element 7 Waters Seal Wash Spring < 2 < 2 -- Third Party Seal Wash Spring < 3 Table 1. Waters and third party seal spring composition comparison. Elemental composition tests using scanning electron microscopy and energy dispersive spectroscopy (SEM-EDAX) were run on the springs inside the two seals. These tests revealed that the spring materials were different. The Waters spring material composition has been developed to resist wear from different solvents (Table 1). The third-party seal spring may not have that same solvent resistance. Waters Critical Clean Process The Waters Critical Clean process is a key differentiation between Waters brand ACQUITY UPLC parts and non-waters parts. This process is a structured manufacturing strategy that Waters has put into place to ensure the highest quality parts are produced. It covers a broad range of areas such as monitoring the compliance of our vendors who makes parts or materials for us, working with design engineering to determine which parts should be critically cleaned, performing audits of part cleanliness, and establishing procedures for handling parts in the field. In Waters manufacturing areas, the critical clean parts are subjected to chemical cleaning followed by multiple ultrasonic rinses and filtration to remove particulates and contaminants that the part comes in contact with while being manufactured. Having clean components is important because the ACQUITY UPLC System sub-2-μm hybrid particle chemistry provides up to 70% higher sensitivity in results when compared to analyses performed with traditional 5-µm particle HPLC chemistries. 4 This higher sensitivity enables chromatographers to clearly see much smaller levels of components in their analyses. Thus, what could be an acceptable level of particulate matter in an HPLC analysis is not acceptable for UPLC. Waters developed specifications and protocols to ensure these parts are handled properly from creation right through to installation in a customer s lab. Replacement Part Packaging As part of the Waters Critical Clean process, all Waters parts used in a system s fluidic path are packaged in clean room approved contaminant free bags. The third-party parts that Waters inspected (seals, backup washers, rotors and solvent filters) were packaged in standard plastic bags. These plastic bags frequently have antistatic, antioxidants, or mold release agents which could leave a residue on the part and once contamination is introduced into the fluid path of a system, it can be difficult and time-consuming to remove. 5 Waters Critical Clean Process Benefits Using Waters Critical Clean parts in your ACQUITY UPLC System can provide you with some immediate benefits: Streamlined installation process parts are ready to be installed and used immediately. No need to flush a system for a long period of time to clean new parts Reduced contamination issues eliminates time spent troubleshooting on contamination issues Putting green initiatives to work reduces the amount of solvent used to flush a system Waters Quality Parts, the Total Solution The measure of system performance is the highest quality in analytical results and throughput. Waters parts ensure that a system designed for total performance will run at optimum efficiency. The introduction of reverse engineered replacement parts into a Waters ACQUITY UPLC System will seriously degrade UPLC performance over time. Using Waters Quality Parts gives you peace of mind that you are protecting your investment and not invalidating your warranty coverage. If it is not from Waters, it is not a Waters Quality Part. Waters maintains several analytical labs worldwide to support critical clean operations and has qualified several manufacturing facilities around the world to manufacture, assemble and perform parts cleaning per Waters Critical Clean specifications. 5

6 References 1. Y. Yang, C.C. Hodges, Assay Transfer from HPLC to UPLC for Higher Analysis Throughput, Chromatographyonline.com, May R. Plumb, Improve the Productivity and Information Content of your Mass Spectrometer with UPLC, Presentation at ASMS UPLC: New Boundaries for the Chromatography Laboratory, EN, May UltraPerformance by Design, EN, Aug Controlling Contamination in UltraPerformance LC/MS and HPLC/MS Systems, Waters, ACQUITY UPLC, UPLC, and Waters Quality Parts are registered trademarks of Waters Corporation. The Science of What s Possible and Waters Critical Clean are trademarks of Waters Corporation. All other trademarks are the property of their respective owners Waters Corporation. Produced in the U.S.A. February EN LB-PDF Waters Corporation 34 Maple Street Milford, MA U.S.A. T: F: