CRM Solutions

How to Digest 316 Stainless Steel for ICP Analysis Using the ColdBlock Digestion System

[fa icon="calendar"] Jan 30, 2018 5:40:25 PM / by Dave Coler

Dave Coler

 

The ColdBlock system uses infrared radiation to rapidly digest metal alloy samples and a cooling block to condense out escaping vapors minimizing the loss of volatile elements.  Our preliminary results, detailed in a previous blog post (A New Sample Preparation Technique for  Metal Alloys), looked promising so we are now conducting validation studies with IARM CRM’s of various alloys.  This post details our validation study using CRM IARM 5I, a Grade 316 stainless steel alloy.

Digestion Procedure

5 separate 0.5g aliquots of CRM IARM 5I were prepared using 20ml of aqua regia in a quartz digestion tube.  The 5 digestion vessels were loaded into a 6 position ColdBlock digestion system and digested for 15 minutes at 28% power.  The digested samples were diluted to a total volume of 50ml using deionized water and transferred to a centrifuge tube.  1 ml of HF was then added to each centrifuge tube to stabilize the solution. The samples were then analyzed on a Spectro Arcos ICP-OES in our laboratory.  The results are detailed below.  The reproducibility of each of the 5 digestions is very good, and the average values agree well with the certified values for all elements including Si and volatile elements such as As and S.     We will be posting the resuts of  validation studies on other alloys in the near future so subscribe to our blog to be sure you are automatically notified.

If you would like to learn more about this technology you can visit our product page Learn More

 

ColdBlock in Lab

ColdBlock Digestion System in ARMI Lab

 

 

 

 

 

 

 

 

                                 Sample in Aqua regia at time = 0                                    

ColdBlock IARM 5I  CRM 316 Stainless Steel Digestion Test
 
Sample after 5 minutes of digestion time
 
Digestion Test IARM 5I CRM 316 Stainless Steel

 

Diluted sample after 15 minutes of digestion time

ColdBlock Digestion Test CRM IARM 5I 316 Stainless Steel

 

IARM -5I Stainless Steel Grade 316
   Co Standard Deviation     Ti   Standard Deviation
Run #1 0.18448 0.00409   Run #1 0.00215 0.00000
Run #2 0.18744 0.00597   Run #2 0.00179 0.00000
Run #3 0.18842 0.00343   Run #3 0.00189 0.00002
Run #4 0.18645 0.00282   Run #4 0.00194 0.00001
Run #5 0.18250 0.00651   Run #5 0.00191 0.00001
Average 0.18586 0.00456   Average 0.00194 0.00001
Certified Value 0.185+/-0.001   Certified Value 0.0025+/-0.0009
             
   Cr Standard Deviation     Al   Standard Deviation
Run #1 16.7000 0.1963   Run #1 0.00454 0.00005
Run #2 16.6400 0.2765   Run #2 0.00447 0.00013
Run #3 16.5800 0.0735   Run #3 0.00462 0.00002
Run #4 16.6500 0.1091   Run #4 0.00454 0.00007
Run #5 16.4900 0.2255   Run #5 0.00447 0.00004
Average 16.6120 0.1762   Average 0.0045 0.00006
Certified Value 16.67+/-0.02   Certified Value 0.004+/-0.001
             
  Mo Standard Deviation     As  Standard Deviation
Run #1 1.9820 0.0317   Run #1 0.00509 0.00000
Run #2 1.9840 0.0261   Run #2 0.00380 0.00000
Run #3 1.9930 0.0100   Run #3 0.00457 0.00000
Run #4 1.9830 0.0096   Run #4 0.00460 0.00000
Run #5 1.9830 0.0153   Run #5 0.00454 0.00000
Average 1.9850 0.0185   Average 0.00452 0.00000
 Certified Value  2.027+/-0.003     Certified Value   0.006+/-0 .001
             
  Ni Standard Deviation     V   Standard Deviation
Run #1 10.1300 0.1165   Run #1 0.06299 0.00028
Run #2 10.1200 0.1747   Run #2 0.06438 0.00031
Run #3 10.0400 0.0275   Run #3 0.06267 0.00035
Run #4 10.1200 0.0867   Run #4 0.06336 0.00027
Run #5 10.0200 0.1659   Run #5 0.06350 0.00019
Average 10.0860 0.1143   Average 0.06338 0.00028
Certified Value 10.04+/-0.03   Certified Value 0.064+/-0.002
             
avg Mn Standard Deviation     Si   Standard Deviation
Run #1 1.4430 0.0080   Run #1 0.44330 0.00323
Run #2 1.4680 0.0130   Run #2 0.45730 0.00050
Run #3 1.4550 0.0184   Run #3 0.43360 0.00350
Run #4 1.4410 0.0367   Run #4 0.42540 0.00041
Run #5 1.4520 0.0069   Run #5 0.41890 0.00098
Average 1.4518 0.0166   Average 0.43570 0.00173
Certified Value 1.443+/-0.009   Certified Value 0.433+/-0.004
             
  Cu   Standard Deviation     Nb   Standard Deviation
Run #1 0.48054 0.00005   Run #1 0.01405 0.00008
Run #2 0.48474 0.00005   Run #2 0.01434 0.00002
Run #3 0.47920 0.00005   Run #3 0.01394 0.00010
Run #4 0.48049 0.00005   Run #4 0.01422 0.00001
Run #5 0.48164 0.00005   Run #5 0.01467 0.00002
Average 0.48132 0.00005   Average 0.01424 0.00005
Certified Value 0.487+/-0.003   Certified Value 0.0133+/- 0.0009
             
  P   Standard Deviation        
Run #1 0.02809 0.00019        
Run #2 0.02916 0.00026        
Run #3 0.02837 0.00030        
Run #4 0.02814 0.00021        
Run #5 0.02805 0.00019        
Average 0.02836 0.00023        
Certified Value 0.0279+/-0.0005        

 


 

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Topics: stainless steel alloys, icp sample preparation

Dave Coler

Written by Dave Coler

General Manager at LGC ARMI