Extraction and analysis of phenolics in food

http://homepages.see.leeds.ac.uk/~earlgb/Publications/Benning_chem_geol_FeS_2000.pdf

Reaction pathways in the Fe-S system below 100°C

/pdf/the-clinical-determination-of-protein-bound-iodine-26ibgkrsfi.pdf

The clinical determination of protein-bound iodine.

The chloric acid method is most commonly used to obtain accurate and reproducible measurements of iodine and remove interfering substances. Unfortunately chloric acid is a potential hazard, requiring an explosion-proof hood, among other precautions. We have developed a simple, convenient, and economic method for measuring urinary iodine by using 1 mol/L ammonium persulfate, a nonexplosive, nonhazardous chemical, as the oxidizing reagent. The oxidation procedure can be completed in 30 min at a temperature of 91-95 degrees C. The iodine in the urine is then measured by a modification of the traditional colorimetric method of Sandell and Kolthoff. Urine samples (110) collected from a mixed population of healthy males and females, ranging in age from 6 to 79 years and living in the US, were analyzed for urine iodine content by two methods: the proposed ammonium persulfate method and the chloric acid method. The ammonium persulfate method has an intraassay CV of 9.1% at 0.42 +/- 0.04 micromol/L (mean +/- SD), 7.8% at 1.46 +/- 0.11 micromol/L, and 4.0% at 3.54 +/- 0.14 micromol/L. The interassay CV is 10.2% at 0.46 +/- 0.05 micromol/L, and 7.9% at 3.27 +/- 0.26 micromol/L. Recovery of iodine added to urine in vitro was 107%, 94%, and 97% for 0.42 micromol/L, 0.77 micromol/L and 3.64 micromol/L, respectively. The lower limit of detectability was 0.0034 microgram of iodine. Values for iodine in 110 urines measured by the reference chloric acid method ranged from 0.06 to 8.03 micromol/L and by the ammonium persulfate method from 0.05 to 7.4 micromol/L. The persulfate method (y) correlated extremely closely with the reference chloric acid method (x) by the Pearson correlation (y = 0.923x + 0.810 micromol/L, and r = 0.994, Sy/x = 1.841).

/pdf/ammonium-persulfate-a-safe-alternative-oxidizing-reagent-for-27f4qsiqsg.pdf

Ammonium persulfate: a safe alternative oxidizing reagent for measuring urinary iodine

Urinary iodine excretion is currently the most convenient laboratory marker of iodine deficiency Accelerating international interest in correcting this condition demands rapid, simple methods for 

Two Simple Methods for Measuring Iodine in Urine

A procedure is described for the determination of quantities of iodide of the order of 0,05 to 3γ in 1 ml. solution or in a suitable amount of solid sample (sodium chloride). The method is based upon the strong catalytic effect of iodide upon the reaction between ceric sulfate and an excess of arsenious acid in dilute sulfuric acid (1,5–2N). The effect of temperature and foreign substances has been investigated and procedures have been given which are applicable in the presence of salts affecting the rate of the catalyzed reaction. By refinement of the experimental technique it should be possible to determine quantities of iodine much smaller than 0,05γ.

Micro determination of iodine by a catalytic method

Studies on Aging and Properties of Precipitates. XXIII. The Postprecipitation of Ferrous Sulfide with Cupric Sulfide

A critical study has been made ofR. Berg andO. Wurm's method for the determination of bismuth as HBiJ4 oxin. The indirect method in which the excess of iodide is back titrated is recommended particularly in the determination of very small amounts of bismuth. Low results are obtained when the chloride concentration is greater than about 0,1N in the final mixture.

The volumetric determination of bismuth as bismuth-hydrogen iodide-oxin

Studies on Aging and Properties of Precipitates. XXII. The Induced Precipitation of Mercuric Sulfide from Sodium Mercuric Sulfide Solutions by Zinc Sulfide. A New Case of Postprecipitation

I. M. Kolthoff

Papers

Micro determination of iodine by a catalytic method

Studies on Aging and Properties of Precipitates. XXIII. The Postprecipitation of Ferrous Sulfide with Cupric Sulfide

The volumetric determination of bismuth as bismuth-hydrogen iodide-oxin

Studies on Aging and Properties of Precipitates. XXII. The Induced Precipitation of Mercuric Sulfide from Sodium Mercuric Sulfide Solutions by Zinc Sulfide. A New Case of Postprecipitation

The postprecipitation of zinc sulfide with bismuth sulfide1