Yes, regia could passivate silver surface and so the erosion stops. To my experience, hot 1-2M HNO3 accompanied with ultrasonication is quite efficient to remove these silver nanoparticles
Yes, regia could passivate silver surface and so the erosion stops. To my experience, hot 1-2M HNO3 accompanied with ultrasonication is quite efficient to remove these silver nanoparticles
Thanks everyone! I try to dissolve the particles to measure the exact concentration in the sediment with ICP-OES so I don't care about the matrix really. I used 65% HNO3 accompanied with ultrasonication at 65C, this seems to passivate the particles.
Thanks everyone! I try to dissolve the particles to measure the exact concentration in the sediment with ICP-OES so I don't care about the matrix really. I used 65% HNO3 accompanied with ultrasonication at 65C, this seems to passivate the particles.
well, am not familiar with the constituents of your matrix,but I measure AgNPs in ICP OES which are in organic matrix. For that case, acid digestion (Conc Nitric acid) plus Hydrogen peroxide should do as the goal is to get all silver in to ionic by oxidation. I don't think Sulfuric acid should be used, as you might see silver sulfides there! You said that you used Aquaregia (one part of HNO3 and 3 parts of HCl) . I am wondering, won't you risk AgCl formation with this combination ? Will this explain your wrong concentrations?
well, am not familiar with the constituents of your matrix,but I measure AgNPs in ICP OES which are in organic matrix. For that case, acid digestion (Conc Nitric acid) plus Hydrogen peroxide should do as the goal is to get all silver in to ionic by oxidation. I don't think Sulfuric acid should be used, as you might see silver sulfides there! You said that you used Aquaregia (one part of HNO3 and 3 parts of HCl) . I am wondering, won't you risk AgCl formation with this combination ? Will this explain your wrong concentrations?
I am not sure if I understood correctly - you want to retreat the matrix and do not care about AgNPs? If so maybe try piranha (if your matrix will survive that) or thiols which should catch silver. Even ammonia should be useful. Eventually if your matrix is very fragile and do not consist of metal ions (except silver) you can try to complex Ag with EDTA. Hope it helpes. Good luck :)
I am not sure if I understood correctly - you want to retreat the matrix and do not care about AgNPs? If so maybe try piranha (if your matrix will survive that) or thiols which should catch silver. Even ammonia should be useful. Eventually if your matrix is very fragile and do not consist of metal ions (except silver) you can try to complex Ag with EDTA. Hope it helpes. Good luck :)
I think silver nano particles can't be dissolved in its elemental stage. it can be stabilized by using some stabilizer like PVP,CMC etc. If you treat it with Aqua regia then the nano particle can reacts with HNO3 to give the silver nitrate which is water soluble indeed. though AgCl pptd out in some extent depending on HCl conc.
I think silver nano particles can't be dissolved in its elemental stage. it can be stabilized by using some stabilizer like PVP,CMC etc. If you treat it with Aqua regia then the nano particle can reacts with HNO3 to give the silver nitrate which is water soluble indeed. though AgCl pptd out in some extent depending on HCl conc.
In the plating industry, it is common to strip silver using a solution of 90% sulfuric acid / 10% nitric acid. The solution does not need to be heated.
In the plating industry, it is common to strip silver using a solution of 90% sulfuric acid / 10% nitric acid. The solution does not need to be heated.
Protocol I used: 1) culture of endophytes in 250 mL flask using LB media for 48 hrs at 37 deg C, 2) centrifuge at 10,000 rpm for 10 min, 3) AgNO3 solution (1 mM) added into 100 mL filtrate (1:1, v/v), 4) addition of PVP (5 mL, 1% w/v), 5) Incubation at room temperature in an incubator shaker (180 rpm).
Protocol I used: 1) culture of endophytes in 250 mL flask using LB media for 48 hrs at 37 deg C, 2) centrifuge at 10,000 rpm for 10 min, 3) AgNO3 solution (1 mM) added into 100 mL filtrate (1:1, v/v), 4) addition of PVP (5 mL, 1% w/v), 5) Incubation at room temperature in an incubator shaker (180 rpm).
better to try with low pH solvents.
better to try with low pH solvents.
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Please see attached file.
Please see attached file.
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Yes, regia could passivate silver surface and so the erosion stops. To my experience, hot 1-2M HNO3 accompanied with ultrasonication is quite efficient to remove these silver nanoparticles
Yes, regia could passivate silver surface and so the erosion stops. To my experience, hot 1-2M HNO3 accompanied with ultrasonication is quite efficient to remove these silver nanoparticles
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VOTE
Thanks everyone! I try to dissolve the particles to measure the exact concentration in the sediment with ICP-OES so I don't care about the matrix really. I used 65% HNO3 accompanied with ultrasonication at 65C, this seems to passivate the particles.
Thanks everyone! I try to dissolve the particles to measure the exact concentration in the sediment with ICP-OES so I don't care about the matrix really. I used 65% HNO3 accompanied with ultrasonication at 65C, this seems to passivate the particles.
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VOTE
well, am not familiar with the constituents of your matrix,but I measure AgNPs in ICP OES which are in organic matrix. For that case, acid digestion (Conc Nitric acid) plus Hydrogen peroxide should do as the goal is to get all silver in to ionic by oxidation. I don't think Sulfuric acid should be used, as you might see silver sulfides there! You said that you used Aquaregia (one part of HNO3 and 3 parts of HCl) . I am wondering, won't you risk AgCl formation with this combination ? Will this explain your wrong concentrations?
well, am not familiar with the constituents of your matrix,but I measure AgNPs in ICP OES which are in organic matrix. For that case, acid digestion (Conc Nitric acid) plus Hydrogen peroxide should do as the goal is to get all silver in to ionic by oxidation. I don't think Sulfuric acid should be used, as you might see silver sulfides there! You said that you used Aquaregia (one part of HNO3 and 3 parts of HCl) . I am wondering, won't you risk AgCl formation with this combination ? Will this explain your wrong concentrations?
More
VOTE
I am not sure if I understood correctly - you want to retreat the matrix and do not care about AgNPs? If so maybe try piranha (if your matrix will survive that) or thiols which should catch silver. Even ammonia should be useful.
Eventually if your matrix is very fragile and do not consist of metal ions (except silver) you can try to complex Ag with EDTA.
Hope it helpes. Good luck :)
I am not sure if I understood correctly - you want to retreat the matrix and do not care about AgNPs? If so maybe try piranha (if your matrix will survive that) or thiols which should catch silver. Even ammonia should be useful.
Eventually if your matrix is very fragile and do not consist of metal ions (except silver) you can try to complex Ag with EDTA.
Hope it helpes. Good luck :)
More
VOTE
I think silver nano particles can't be dissolved in its elemental stage. it can be stabilized by using some stabilizer like PVP,CMC etc. If you treat it with Aqua regia then the nano particle can reacts with HNO3 to give the silver nitrate which is water soluble indeed. though AgCl pptd out in some extent depending on HCl conc.
I think silver nano particles can't be dissolved in its elemental stage. it can be stabilized by using some stabilizer like PVP,CMC etc. If you treat it with Aqua regia then the nano particle can reacts with HNO3 to give the silver nitrate which is water soluble indeed. though AgCl pptd out in some extent depending on HCl conc.
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I usually use 1:1 of Ammonia 30% and hydrogen peroxide 30%, very exothermic reaction.
I usually use 1:1 of Ammonia 30% and hydrogen peroxide 30%, very exothermic reaction.
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In the plating industry, it is common to strip silver using a solution of 90% sulfuric acid / 10% nitric acid. The solution does not need to be heated.
In the plating industry, it is common to strip silver using a solution of 90% sulfuric acid / 10% nitric acid. The solution does not need to be heated.
More
VOTE
Protocol I used: 1) culture of endophytes in 250 mL flask using LB media for 48 hrs at 37 deg C, 2) centrifuge at 10,000 rpm for 10 min, 3) AgNO3 solution (1 mM) added into 100 mL filtrate (1:1, v/v), 4) addition of PVP (5 mL, 1% w/v), 5) Incubation at room temperature in an incubator shaker (180 rpm).
Protocol I used: 1) culture of endophytes in 250 mL flask using LB media for 48 hrs at 37 deg C, 2) centrifuge at 10,000 rpm for 10 min, 3) AgNO3 solution (1 mM) added into 100 mL filtrate (1:1, v/v), 4) addition of PVP (5 mL, 1% w/v), 5) Incubation at room temperature in an incubator shaker (180 rpm).
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