I used ICP-OES for mineral analysis in food samples. i digested 1g sample in 8ml of triacid mixture and made up volume to 100ml with dist.water. I got the ICP-OES values in ppm. I used 50ml for analysis. How to calculate dilution factor for this? which is diultion factor for this? Whether 8 ml acid or whole 100ml ? Whether we can represent the results using arbitary mass unit (g/100g). Read many references and didnot got clarity about this. Kindly provide your valuable suggestions.
The final volume of food digest diluent, submitted to ICP-OES, was 100 mL.
Say, the estimated mineral levels in food was X ppm or X mg/kg (Note: 1 ppm = 1 mg/kg).
*Remember, 1 kg (water) = 1 L (water) (Note: Density of water = 1 kg/L @ 25 C)
Therefore, Mineral levels (in food diluent of volume 100 mL) = X mg/kg = X mg/L = X mg/1000 mL = 0.X mg/100 mL
Since, 1 g food was digested and later diluted to 100 mL, therefore, it is implied that the mineral levels estimated in 100 mL diluent is equivalent to mineral levels in 1 g food.
Mineral levels (in food) = 0.X mg/g = 10X/100 g
Hope it helps and gives you better understanding of unit conversions.
Cheers... :)
=((icp answer*0.1(for the make up volume )*100(for /100g) the n divide the whole thing by sample mass.your answer will be in mg/100g
if your did some other dilutions from the initial 100 ml then multiply the answer by the dilution factor
Is a simple, general "rule" or calculating method.
1. You give the sample weight in [g] (In your case 1 g)
2. You give the final volume (after digestion) in [ml] (In this case 100 ml)
Note: the volume of acid for digestion isn't important, and the volume used for analysis (50ml) also not important (if there was not a further dilution from 100 ml).
3. The calculating factor = volume / weight = 100 / 1 = 100 [ml/g]
4. Your final result in [mg/kg = ppm] in original (solid or not) food sample will be (for example the measured ICP-OES result was = 4.5 mg/l potassium)
ICP-OES result in [ppm = mg/l] * calculating factor
= 4.5 mg/l * 100 ml/g = 450 mg/kg !!!!
Because the calculating factor 100 ml/g = 100 l/kg !!!!
and mg/l * l/kg = mg/kg !!!!
Explanation: if you give the sample weight in kg and final volume in liter
(in this case 0.001 kg and 0.1 liter) the calculating factor will be
0.1 liter / 0.001 kg = 100 liter/kg (= the same number = 100 ml/g)
and your final result = 4.5 mg/l * 100 l/kg = 450 mg/kg.
To calculate the result for 100 g original food sample - divide that by 10.
(potassium content =) 45 mg per 100 g food.
If You understand this simple general rule (points 1.-4.), it can be an unforgettable automatic routine, and you never will make a mistake.
I used ICP-MS for Pd quantity (wt %) in catalyst Pd/SiO2. i digested 12.9 mg of sample in 6 ml of triacid mixture and made up volume to 50 ml with dist.water. From the 50 mL solution, I took 200 ul of solution and makeup with 25 mL volumetric flask and used for analysis. Moreover, i used 500, 1000, 2000 ppb standards of Pd. I got ICP-MS value of Pd/SiO2 is 231.5719. How to calculate weight % of Pd? Kindly provide your valuable suggestions. If any further information requires please let me know. For your reference i attached icp-ms results please check the same and suggest me.Thank you
@ Zoltan Sandor Hello Professor hope you are fine! I have did ICP-MS to know the concentration of Pt, I used 5 mg of sample and dissolve in 2 mL HCL: 7 mL HNO3, after complete digestion, I made 100 mL solution and I used this solutions without diluting it. I got 39.1 ppb from the ICP-MS machine. Kindly tell me how to calculate weight % of Pt?
Dear all,
simply do as following
B: mass of digested sample (g)
V: final volume (100ml)
concentration in mg/kg = (ICP value *100 ml)/B
if you want the result in wt % just divide the mg/kg by 10000
- Badges
- Science method
- Similar topics
- Methodology
- Crystallography
- X-ray Diffraction