NEWS Aqueous Solutions without HF or Organic Solutions Limited Volume or Volatile Solvent? ICP-MS ICP-OES Yes No MicroMist Solutions Containing HF Instrument type? Particulates? Particulates? >75μm >75μm Yes No Yes No Limited Volume? VeeSpray Yes No Particulates? >75μm Yes No Yes No Yes No VeeSpray SeaSpray VeeSpray Limited Volume? High TDS? >5% Slurry Particulates? >75μm Requirement? Best Performance Routine Operation SeaSpray Conikal Standard OpalMist Low Uptake OpalMist Yes No Standard DuraMist Low Uptake DuraMist Figure 7: Glass Expansion nebulizer selection guide. As shown in Figure 7, sample uptake rate is a factor in the selection of the proper nebulizer. Our online pump speed and sample uptake calculator provides a quick and accurate estimate of your sample uptake rate. If you prefer a real-time continuous measurement of your sample uptake, consider adding the TruFlo Sample Monitor to your ICP laboratory. The TruFlo provides a 24- hour record of performance and reduces the need to repeat measurements due to a blocked nebulizer, worn pump tubing or incorrect clamping of the pump tube. If you require the measurement of trace levels of boron, you might consider using a high purity PFA nebulizer like the OpalMist. We also offer a Quartz Concentric U-Series nebulizer that would be suitable for boron measurements. The performance of the Quartz Concentric U-Series nebulizer is comparable to that of the Conikal nebulizer. Nebulizer Maintenance The lifetime of a nebulizer can be prolonged by proper maintenance. Here are some practices that should be avoided to prevent damage. • Do not insert anything through the orifice of the nebulizer. This is most likely to damage the nebulizer beyond repair. • Do not use any concentration of HF to clean a glass or quartz nebulizer. Even dilute HF can alter the orifice of the internal capillary and deteriorate the performance of the nebulizer. • Do not place a glass nebulizer in an ultrasonic bath as it may dislodge the internal capillary. • Do not use hot liquid to flush the sample capillary of an inert nebulizer. The temperature can potentially deform the capillary and affect nebulizer performance. At the end of each day, it is always best to aspirate dilute acid for 15 minutes followed by deionized water (DIW). This ensures that sample deposits or crystals do not form on the inside of a nebulizer when the solvent dries, which can deteriorate performance and shorten the lifetime. For regular analysis of samples with high TDS we recommend aspirating a 2.5% Fluka RBS-25 (P/N FLU KA25) solution for 15 minutes at the end of each day or analysis run followed by DIW. This will also clean your spray chamber. (For tips on analyzing high TDS samples, see the June 2010 newsletter.) If your nebulizer’s sample capillary becomes blocked, we recommend using the Eluo nebulizer cleaning tool to safely back-flush and unblock your nebulizer (Figure 8). For concentric glass nebulizers, use the standard Eluo nebulizer cleaner, P/N 70-ELUO ; for the OpalMist, PolyCon, and DuraMist use P/N 70-ELUO -OPD ; and for the old design OpalMist and PolyCon use P/N 70-ELUO -OP . If there are salt deposits that cannot be removed with the Eluo, we recommend removing all of the fittings and soaking the nebulizer for 24hrs in a beaker of 25% Fluka solution and then flushing with warm water using the Eluo. After a few flushes with warm water it can then be flushed with methanol so that it will dry faster. Use the Eluo regularly to maintain nebulizer performance and prolong life. When cleaning your nebulizer always take special care of the nebulizer tip. Any deposit of body oils can have a detrimental effect on the performance of the nebulizer, so handle only with gloves. Once a nebulizer tip has been damaged, the nebulizer’s performance cannot be restored. All Glass Expansion nebulizers are supplied in specially designed plastic boxes. The nebulizer should be kept in this box when it is being stored. This prevents damage to the nebulizer tip, and small particles from lodging in the nebulizer bore and causing blockages. The VeeSpray nebulizer is quite rugged and usually only requires minimal maintenance. However, it is still advisable to run dilute acid or DIW at the end of each analysis run. The ceramic body can be isolated and soaked in 25% Fluka if necessary. www.geicp.com Glass Expansion Newsletter | Issue 31 | page 4
Glass Expansion News June 2013
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