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Obnovit | RAW

Laboratory of Elemental Analysis

Sample requirements

required information about the analyzed sample:

  • sample toxicity - if known 
  • sample storage conditions

Best results are achieved if the samples are perfectly homogenised. In the case of some methods, we weight approx. 2 mg of the sample thus sample homogenity has great influence on results of analyses. The lower the element content is, the bigger the sample weight must be used for analysis.

All analyses are done at least three times.

Explanatory notes to all analyses:

1. Simultaneous determination of carbon, hydrogen, nitrogen and sulfur from one sample

Sample amount for one C, H, N, S analysis is in the range of 5 mg and 50 mg depending on the sample origin and composition.

 If your sample contains carbon or sulfur in inorganic form (e.g. CO32-, HCO3-, S2-, SO32-, HSO3- and some SO42-, HSO4- ions) then inorganic bounded element will be also determined. It means that total carbon and total sulfur are always determined. It is impossible to recognize organic and inorganic forms of carbon and sulfur.

If your sample contains fluorine in any form and quantity, then the sulfur content cannot be determined. Fluorine containing samples can be analyzed only by the Vario EL III analyzer. In the case of flourinated samples, we can only do the determination of carbon, hydrogen and nitrogen content.
We need to know if your sample contains fluorine and what is the estimated flourine content.

2. Trace and semi-trace determination of halogens and sulfur

  Sample amount for one analysis varies in the range of 5 mg and 50 mg.

Results are expressed as chlorine content. It is impossible to recognize individual halogen.

Trace determination of halogens (not fluorine) requires sample containig less than 10 wt% S and less than 10 wt% N. In the case of samples of unknown chemical composition, we have to do the simultaneous C, H, N, S determination at first.

Trace determination of sulfur is disturbed by nitrogen and halogens. If the determination has to be done, your samples cannot contain nitrogen and halogens.

Trace determination of halogens (not fluorine) is disturbed by high sulfur and nitrogen content. If the determination has to be done, your samples can contain sulfur and nitrogen up to 10 %wt. In the case of samples of unknown chemical composition, we have to do the simultaneous C, H, N, S determination at first.

3  Determination of chlorine-, bromine- and iodine content

We are able to analyse samples containig more than 0,01 wt% Cl, Br or I. Sample amount needed for one analysis is in the range of 4 -100 mg

Your sample has to be a solid and easy burnable matter.

If the estimated halogen content is bellow 5 wt% then the sample mass needed for one analysis is at least 100 mg. If the estimated halogen content is above 5 wt% then the sample mass needed for one analysis is 20 mg.

 
4. Phosphorus Determination

 We are able to analyse samples containig more than 0,1 wt% P. Sample amount needed for one analysis varies in the range between 500 mg and 10 mg.

Results

Please do not forget that results can be influenced by sample moisture and also by residual solvents. Results are usually sent  via e-mail.

Updated: 1.2.2016 16:31, Author: Josef Chudoba


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