A new technique for radiolabelling of humic substances

Franke, Karsten; Patt, J. T.; Patt, Marianne; Kupsch, H.; Steinbach, Jörg

doi:10.1524/ract.92.4.359.35606

Cited by 6 publications

(6 citation statements)

References 16 publications

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“…Slight modification of HS functional groups was applied for introduction of halogens into HS. The method was used to radiolabel the carbon backbone of HS with 18 F via azo coupling using a precursor (4-[ 18 F]fluorobenzenediazonium ion) [11] and 125 I using a precursor 3-[ 125 I]iodobenzenediazonium ion [12]. The radiohalogen labeled group can react with the polyphenolic groups in the HS.…”

Section: Introductionmentioning

confidence: 99%

A new technique for tritium labeling of humic substances

Badun¹,

Chernysheva

Tyasto

et al. 2010

Radiochimica Acta

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Humic substances (HS) of different origins have been labeled with tritium by the thermal activation method. Specific radioactivity of labeled HS ( 3 H-HS) was sufficiently high and varied from 0.14 to 0.6 TBq/g. Parent HS and 3 H-HS were analyzed by size exclusion chromatography with radioactivity and UV detection. The results allowed concluding that (1) neither partial decomposition nor polymerization of HS occurred during labeling and (2) tritium labeled molecules have a regular distribution among HS fractions of different molecular weights. The performed correlation analysis revealed that there was no significant relationship between HS properties and specific radioactivity of the obtained 3 H-HS. Thus universality of the developed technique for radioactive labeling of HS with tritium could be demonstrated.

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Section: Introductionmentioning

confidence: 99%

A new technique for tritium labeling of humic substances

Badun¹,

Chernysheva

Tyasto

et al. 2010

Radiochimica Acta

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“…The radiochemical yield after HPLC was up to 75%, and step 2 was in total 60%. The diazotization reaction is reported extensively in the literature ,,, . A yield can not be given for the product ( 4 ) because of the high instability of this intermediate.…”

Section: Resultsmentioning

confidence: 99%

“…The radiolabeling of HA ( 6 ) was optimized with respect to (i) the buffer used, (ii) the concentration of HA, and (iii) the method used to purify the radiolabeled HA. According to ref , radiolabeling should be carried out at pH 8. Nevertheless, different buffer systems (borate buffer, phosphate buffer, tris buffer, pH adjusted by means of NaOH/HCl) were tested to determine the optimum radiolabeling conditions.…”

Section: Resultsmentioning

confidence: 99%

“…Secondary reactions may be avoided by using a method that was reported for radiohalogenating amino acids and peptides (28). The method was used to radiolabel the carbon backbone of HS with 18 F via azocoupling using a precursor (4-[ 18 F]fluorobenzenediazonium chloride) (29). The 18 F labeled group (Figure 1) can react with the polyphenolic groups in the HS.…”

Section: Introductionmentioning

confidence: 99%

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Radioiodination of Humic Substances via Azocoupling with 3-[¹²⁵I]Iodoaniline

Franke¹,

Patt

Kupsch

et al. 2008

Environ. Sci. Technol.

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A new method is described for radiolabeling humic substances (HS) with iodine radioisotopes. The method radiolabels the electron-rich aromatic moieties of HS with the 3-[125I]iodobenzenediazonium ion via azocoupling. The method uses four steps: (i) 3-aminobenzenetrimethylstannane is synthesized and isolated by using a silica gel column, (ii) 3-[125I]iodoaniline is synthesized and isolated by HPLC, with radiochemical yields of up to 60%, (iii) 3-[125I]iodobenzenediazonium chloride is synthesized, and the reaction mixture from this step is used in step iv to radioiodinate HS with radiochemical yields of up to 95% (with reference to 3-[125I]iodoaniline). The advantage of this method is that it is selective radiolabeling, placing the radiolabel in a specific site (the 3-position of the phenyl ring) within HS molecules, which minimizes unwanted secondary chemical interactions. Investigations of the stability of the radiolabel and the effect of photoreductive dehalogenation showed that there was a negligible release of 125I. The production of radiolabeled HS using this method allows the sensitive detection of HS in laboratory and field studies. In addition, the method offers the possibility of using different iodine radioisotopes simultaneously in investigations using HS.

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“…Recent examples of this procedure include the preparation of 5- 82 2-[ 18 F]-fluoroisonicotinic acid hydrazide, 83 N,N-dimethyl-2-(2-amino-5-[ 18 F]-fluorophenylthio)benzylamine 84,85 and 4-[ 18 F]-fluoro-N-{2-[4-(6-trifluoromethylpyridin-2-yl)piperazin-1-yl]ethyl}benzamide. 86 In the preparation of 1-bromo-4-[ 18 F]-fluorobenzene nuleophilic aromatic substitution of the iodonium cation proved effective 87 whilst for humic acids, displacement of the diazonium cation 88 was best.…”

Section: Fluorine [ 18 F]mentioning

confidence: 99%