How to clean SPS 4 probe?

Question

I found major deposits within my autosampler probe after doing an analysis with MP-AES which the rinse solution (high purity water) wasn't able to remove.

How do I remove these deposits within both the probe and the autosampler tubing?

Thanks!

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gareth.pearson · Answer

Hi Shane, We have a recommended regeneration procedure for the probe, usually used for ICP-MS to get rid of sticky elements that contribute to the background. Note this is an aggressive strip and clean that you can only perform about 3-times before you will need to replace the probe. 4-step rinse by pumping ~50mL of: Ammonium Hydroxide 1:1 dilution with Ultrapure water conc Nitric acid 1:1 dilution with Ultrapure water conc HCl 1:1 dilution with Ultrapure water Ultrapure water Aim to pump 50ml in 30-40 min each (@1.5mL/min) As Peter mentions suggest relook at your rinse to ensure it is cleaning out your sample matrix sufficiently each time. Hope that helps. Rgds, Gareth

shanegrant · Answer

Hi everyone,

Thank you Peter Riles and Gareth Pearson for the brilliant feedback. Prior to your replies managed to clean the probe effectively by using a very dilute detergent (Hellmanex III) in an ultrasonic batch.

The following method was used:

1. Draw water through the probe into the tubing connected to the probe using a syringe.

2. Submerge the tubing and the probe together into the ultrasonic bath.

3. Ultrasonicate for 15 minutes.

Following this I noticed that the water alone was sufficient to thoroughly clean the probe itself however a small blockage was still observed in the tubing.

4. Add a very small aliquot of detergent into the ultrasonic bath.

5. Using a syringe again, draw the dilute detergent solution into the probe and tubing and submerge fully in the bath.

6. Ultrasonicate for a further 15 minutes.

No deposits remained on/in the probe or tubing.

I then used Peter Riles advice of using the nitric acid (2%) as a rinse solution and this has functioned well at reducing deposit formation. If the need should arise in the future for an aggressive rinse according to Gareth Pearson's contribution, I will keep the method in mind.

Thank you all!

Regards,

Shane

peter.riles · Answer

Hi Shane, What type of samples are you analysing and what is the matrix? I typically prefer to rinse with the same matrix as the samples being analysed. This helps to keep the tubing clean. Once a probe is visibly dirty it can be difficult to clean. I would suggest replacing the probe and using a more aggressive rinse. The minimum i suggest is 2% HNO3, although if you are measuring something basic, a different rinse may be more appropriate. If you want to try to clean the probe running some acid through it may be able to clean it. 10% HNO3 may do what you need. You could use a syringe to connect to the probe to rinse it, or use the autosampler pump. Regards, Peter

How to clean SPS 4 probe?

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