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Selecting emission line for Sn in palm oil analysis
I'm performing validation on solvent (butanol) diluted palm oil using ICP-OES analysis (Method Ca 17 –01 modified). I have validated Tin (Sn) with the following wavelengths: Sn 189.927; 235.485; 242.170; 283.998. The backgrounds for butanol are rather noisy for Sn 189 & 235, and Sn 242 & 283 are getting better backgrounds with low noise. I have better LOD as well for wavelength 283 compared to the rest. However I'm doubtful as Sn concentrations in palm oil samples differ from every wavelength (e.g., Sn 189 = 2.35 ppm, Sn 235 =0.96 ppm; Sn 242 =1.21 ppm; Sn 283 = 0.61ppm). Is there any better guideline for wavelength selection? Can the lowest LOD (0.05ppm) be used as justification to select Sn 283 as an analytical line for Sn even though Sn 189 is recommended?
Created: 09/05/18 22:59:08
Created By: "admin"
2 2755
Selecting emission line for Sn in palm oil analysis
I'm performing validation on solvent (butanol) diluted palm oil using ICP-OES analysis (Method Ca 17 –01 modified). I have validated Tin (Sn) with the following wavelengths: Sn 189.927; 235.485; 242.170; 283.998. The backgrounds for butanol are rather noisy for Sn 189 & 235, and Sn 242 & 283 are getting better backgrounds with low noise. I have better LOD as well for wavelength 283 compared to the rest. However I'm doubtful as Sn concentrations in palm oil samples differ from every wavelength (e.g., Sn 189 = 2.35 ppm, Sn 235 =0.96 ppm; Sn 242 =1.21 ppm; Sn 283 = 0.61ppm). Is there any better guideline for wavelength selection? Can the lowest LOD (0.05ppm) be used as justification to select Sn 283 as an analytical line for Sn even though Sn 189 is recommended?
Posted: 09/05/18 22:59:50
Antimony (Sb) drift in ICV and LCS using ICP-MS
Recently I have experienced both a high and low drift in just Antimony (Sb) in our ICV recovery and now in our LCS recovery. I have tried using new stock standards for the calibration curve and checks and still Antimony will fail (currently high). The concentration for Antimony should be 50 ppb, yesterday I recovered 67 ppb and my 50 ppb LSC spikes were reported at 65 ppb. The LCSs are not spiked by me so there is a third bottle of standard involved. I have seen the antimony drift low at 44.5 ppb last week. Only Antimony is being affected. My internal standard recoveries are excellent, but not used for any correction of elements. What could be causing this behavior?
Created: 09/05/18 22:56:38
Created By: "admin"
1 3949
Antimony (Sb) drift in ICV and LCS using ICP-MS
Recently I have experienced both a high and low drift in just Antimony (Sb) in our ICV recovery and now in our LCS recovery. I have tried using new stock standards for the calibration curve and checks and still Antimony will fail (currently high). The concentration for Antimony should be 50 ppb, yesterday I recovered 67 ppb and my 50 ppb LSC spikes were reported at 65 ppb. The LCSs are not spiked by me so there is a third bottle of standard involved. I have seen the antimony drift low at 44.5 ppb last week. Only Antimony is being affected. My internal standard recoveries are excellent, but not used for any correction of elements. What could be causing this behavior?
Posted: 09/05/18 22:58:05
Zinc interferences on sodium using ICP-OES
I am analyzing samples for sodium (Na) by ICP-OES using the 330.237 nm line at concentrations near the detection limit, and I am having trouble with the repeatability of the measurements. I noticed that your Interactive Periodic Table showed this line could be influenced by the presence of zinc (Zn). Can you provide more information about this interference, as well as how I might improve the reliability of the measurements?
Created: 09/05/18 22:55:35
Created By: "admin"
1 4915
Zinc interferences on sodium using ICP-OES
I am analyzing samples for sodium (Na) by ICP-OES using the 330.237 nm line at concentrations near the detection limit, and I am having trouble with the repeatability of the measurements. I noticed that your Interactive Periodic Table showed this line could be influenced by the presence of zinc (Zn). Can you provide more information about this interference, as well as how I might improve the reliability of the measurements?
Posted: 09/05/18 22:55:56
Silicon measurements by ICP-MS and interferences
I am in the process of developing a method to analyse high purity steam samples from geothermal power stations using ICP-MS. Silicon (from dissolved silica) is an element of major interest as silica deposition can reduce the efficiency of the steam turbines. However, it is difficult to analyse silicon by ICP-MS at m/z 28 due to spectral interferences from N2, which is most likely coming from the nitric acid that I use to acidify the solutions. Which acid would you recommend that I substitute the nitric acid for? And what other steps would you suggest that I take in order to reduce any other spectral interferences for m/z 28 - 30?
Created: 09/05/18 22:54:34
Created By: "admin"
1 13930
Silicon measurements by ICP-MS and interferences
I am in the process of developing a method to analyse high purity steam samples from geothermal power stations using ICP-MS. Silicon (from dissolved silica) is an element of major interest as silica deposition can reduce the efficiency of the steam turbines. However, it is difficult to analyse silicon by ICP-MS at m/z 28 due to spectral interferences from N2, which is most likely coming from the nitric acid that I use to acidify the solutions. Which acid would you recommend that I substitute the nitric acid for? And what other steps would you suggest that I take in order to reduce any other spectral interferences for m/z 28 - 30?
Posted: 09/05/18 22:54:52
Certification and validation of reference materials
How do we know that the tested (certified) elements are really the ones present in the standards? And how are the concentrations tested?
Created: 09/05/18 22:53:21
Created By: "admin"
1 2592
Certification and validation of reference materials
How do we know that the tested (certified) elements are really the ones present in the standards? And how are the concentrations tested?
Posted: 09/05/18 22:53:52
Internal standard for Pd, Rh, Cu, and Li
We are currently developing a method for Pd, Rh, Cu, and Li. We have previously used an yttrium internal standard, but have been receiving samples with a residual basic pH that has caused problems with our runs, ending with the exclusion of the internal standard yttrium. I then saw on this site that yttrium and basicity do not get along. Do you have any advice on other possible internal standards that work fine in a variety of pH?
Created: 09/05/18 22:52:03
Created By: "admin"
1 2401
Internal standard for Pd, Rh, Cu, and Li
We are currently developing a method for Pd, Rh, Cu, and Li. We have previously used an yttrium internal standard, but have been receiving samples with a residual basic pH that has caused problems with our runs, ending with the exclusion of the internal standard yttrium. I then saw on this site that yttrium and basicity do not get along. Do you have any advice on other possible internal standards that work fine in a variety of pH?
Posted: 09/05/18 22:52:36
Control sample failure in ICP-OES measurement
In an ICP-OES measurement, if the control sample of the analysis fails, what is the remedial action?
Created: 09/05/18 22:50:58
Created By: "admin"
1 2611
Control sample failure in ICP-OES measurement
In an ICP-OES measurement, if the control sample of the analysis fails, what is the remedial action?
Posted: 09/05/18 22:51:20
Positive interference mercury (Hg) mass 202
I've noticed that tungsten can cause a positive interference with mercury isotope at mass 202. Can you offer a good correction equation to reliably counter this effect?
Created: 09/05/18 22:49:44
Created By: "admin"
1 3206
Positive interference mercury (Hg) mass 202
I've noticed that tungsten can cause a positive interference with mercury isotope at mass 202. Can you offer a good correction equation to reliably counter this effect?
Posted: 09/05/18 22:50:12
Uncertainty in ICP water analyses
Can you please supply the methodology for the uncertainty of measurement for ICP and ICP-MS analyses of water?
Created: 09/05/18 22:48:33
Created By: "admin"
1 2679
Uncertainty in ICP water analyses
Can you please supply the methodology for the uncertainty of measurement for ICP and ICP-MS analyses of water?
Posted: 09/05/18 22:48:57
Differences between tuning and wavelength calibration standards
Are there any actual differences in uses between IV-STOCK-24 and IV-STOCK-55? We're being asked to create an “ICP OES & MP-AES wavecal solution“ but the specified ingredients and concentrations match the tuning solution IV-TOCK-24.
Created: 09/05/18 22:47:00
Created By: "admin"
1 2607
Differences between tuning and wavelength calibration standards
Are there any actual differences in uses between IV-STOCK-24 and IV-STOCK-55? We're being asked to create an “ICP OES & MP-AES wavecal solution“ but the specified ingredients and concentrations match the tuning solution IV-TOCK-24.
Posted: 09/05/18 22:47:51