test for thiocyanate

Thiocyanate Test Code SACYN Specimen Type Serum - Gel Minimum Volume 1mL Assay Performed Biochemistry Dept Alfred Hospital Commercial Road Prahran 3181 VIC 03 9076 3888 Assay Frequency As requested. Cyanogen content of cassava roots and flour in Indonesia. Satisfactory agreement was found between the simple visual comparison and the more accurate measurement of absorbance. 1.1 This test method covers the quantitative colorimetric laboratory measurement of dissolved thiocyanate in water, waste water, and saline water in the range from 0.1 to 2.0 mg/L. The cobalt thiocyanate test (or Scott test) is a proven screening test for the presence of cocaine. It is a pseudohalide anion and a sulfur molecular entity. It is a layered coordination complexand its trihydrate Co(SCN)2(H2O)3is used in the cobalt thiocyanate test(or Scott test) for detecting cocaine. A picrate paper was placed in the vial, which was then closed, and the absorbance was measured according to the method described above. thiocyanate S=C=N– Toxicology A salt of thiocyanic acid that is a breakdown product of cyanide, which is ↑ in smokers, Pts receiving nitroprusside, and victims of smoke inhalation. Its excretion in urine, saliva, and sweat can thus provide a useful marker of exposure in smokers and nonsmokers ()()()().Salivary tests have the advantages of easy, noninvasive sampling and of good stability, even in nondemanding storage conditions (). The cobalt thiocyanate test for cocaine was first introduced by Young in 1931 [2]. These samples were either used the same day or frozen at −20 °C until required for analysis (14). The mean deviation between the two methods was 11%. Cassava products such as cassava flour, which is important in East Africa and Indonesia, and gari, which is important in West Africa, and cassava roots have a total cyanogen content of 0–200 mg HCN equivalents/kg cassava (0–200 ppm) [Ernesto et al., submitted for publication, and Refs. Three different samples of urine gave zero production of cyanide in every case. For 53 urine samples analyzed by an accurate column method and the thiocyanate picrate method, a regression line gave very good agreement (r2 = 1.000). Urine samples were obtained from volunteer donors in Canberra, including adult males and females, smokers and nonsmokers, and children. May include related or preferred tests. To cover the full range of thiocyanate content (0–100 mg/L) that is obtained in urine samples from cassava-eating populations, 5, 10, 20, 40, 60, 80, and (in one case) 100 mg/L thiocyanate was added to four different urine samples. In: Liener IE, ed. No other units of measurement are included in this standard. We thank Dr. Julie Cliff for useful discussions and particularly for suggesting the importance of the development of a simple method for thiocyanate in urine. The papers that contained 0, 1, 2, 4, 6, 10, 20, 40, 60, and 100 mg/L were aligned on a chart. For higher concentrations, use an aliquot from the diluted sample. The method was not affected by the presence of potentially interfering compounds present in the urine, such as protein at <7 g/L, 21 amino acids, histamine, glucose, sodium chloride, urea, blood, and linamarin. Determination of thiocyanate in body fluids. It is a conjugate base of an isothiocyanic acid and a thiocyanic acid. Cobalt(II) thiocyanateis an inorganic compoundwith the formula Co(SCN)2. A new volumetric method of cerium determination by thiocyanate. The color of the blank should correspond to zero on the chart, and the controls should correspond to 4 or 40 mg/L. Other soluble constituents of urine were removed by washing with water. For the four urine samples, the mean (SD) recoveries of thiocyanate from the addition of 5, 10, 20, 40, 60, and 80 mg/L were 104% (4%), 105% (6%), 103% (2%), 105% (2%), 103% (2%), and 103% (2%), respectively. (11) was followed with several changes. 3. Duplicate analyses were made at each concentration, and these were scored using the simple color chart by two independent observers. However, it contains a cyanogenic glucoside, linamarin, that is hydrolyzed in two steps: the linamarin is first hydrolyzed to acetone cyanohydrin and glucose (catalyzed by the enzyme linamarase), and then the acetone cyanohydrin is hydrolyzed to acetone and hydrogen cyanide (HCN). For specific hazard statements, see Section 9. The paper was eluted for ∼30 min in 5.0 mL of water with occasional stirring, and the absorbance of the solution was measured at 510 nm in a spectrophotometer against a blank solution prepared from an unchanged picrate paper similarly eluted. The iron(II) chloride should be rusty brown and the potassium thiocyanate should be white 3. Mercury(II) thiocyanate was formerly used in pyrotechnics. With all four urine samples, there was no change in the HCN content with protein concentrations of 0, 0.3, 1, 3, and 5 g/L. A 30 × 10 mm picrate paper, attached to a 50 × 10 mm plastic strip with hobby glue, was added to the vial, which was then closed. 5.1.1 For information on the impact of cyanogens and cyanide compounds, see Appendix X1 of Test Methods D2036. Alternatively you can use a large beaker to hold them. Duplicate 1-mL samples of urine containing blood concentrations giving reagent strip values of 0, trace, 25, 80, and 200 were then set up and analyzed for thiocyanate using the standard reaction conditions. Conclusions: A simple picrate kit for determination of thiocyanate in urine was developed and is available free of charge for workers in developing countries. 1.1.1 Validation— This test method was validated over the range of 0.07 to 1.42 mg/L. Especially for chronic exposure to low cyanide concentrations, such as occur for example in smoking and at anumber of workplaces, thiocyanate in plasma and saliva is asui-table biomarker. Short reaction times (3 and 6 h) were found to give low results for thiocyanate in some cases, whereas 16 h always gave good results. The picrate method and a column method were compared using 53 urine samples, and a very good regression line was obtained (see Fig. Thiocyanate is a pseudohalide anion obtained by deprotonation of the thiol group of thiocyanic acid. test methods for cyanides in water - automated methods for total cyanide, weak acid dissociable cyanide, and thiocyanate ASTM D 3670 : 1991 : Test methods for fibre-reinforced cementitious composites -- Bending moment--curvature curve by four-point bending test A 30 × 10 mm picrate paper, attached to a plastic strip with hobby glue (6), was immediately added to the vial, and the vial was closed with a screw cap. Sodium perchlorate (Analar grade; BDH), sodium hypochlorite solution (125 g/L, technical grade; APS Ajax Fine Chemicals), isonicotinic acid (Sigma), 1,3-dimethylbarbituric acid (Fluka), and AG3-X4 anion-exchange resin (100–200 mesh, free base; Bio-Rad Laboratories) were used in the column method (11). which was obtained from Eq. In preliminary experiments, KSCN solution was reacted with KMnO4, K2Cr2O7, or Ce(SO4)2 in dilute H2SO4 in the presence and absence of urine (1 mL) in a 25 × 50 mm, flat-bottomed polystyrene vial with a polyethylene screw cap (Techno Plas). In the laboratory, a more accurate result was obtained by elution of the colored complex in water and measurement of the absorbance at 510 nm. 1.1.1 Validation—This test method was validated over the range of 0.07 to 1.42 mg/L. Results are expressed as ppm (mg/L) Cl-. Using six different samples of urine, we found that the amount of linamarase used must be approximately threefold higher than the amount of linimarase used with cassava present to obtain complete hydrolysis of linamarin and quantitative recovery of HCN. Cardoso AP, Ernesto M, Cliff J, Egan SV, Bradbury JH. Quantitative recoveries of thiocyanate added to urine samples were obtained with the picrate method. Clearly, the thiocyanate content of urine samples is constant for at least 7 days at 20–30 °C, at least 14 days at 4 °C, and at least 6 months at −20 °C. To obtain a more accurate result, the plastic strip was removed from the picrate paper, which was immersed in 5.0 mL of water for about 30 min. Measure 20 ml of water into the measuring cylinder and pour it into the beaker containing the iron(III) chloride. Under these conditions, there was no appreciable reaction of the 21 amino acids and histamine (0.2–2 mg of each used in the tests) with permanganate in acid solution to produce HCN. Support us The Royal Children's Hospital Melbourne. For semiquantitative analysis in the field, the colored picrate paper was matched with a color chart prepared using known amounts of KSCN. Alkali-thiocyanate is a sensitive reagent for the detection of cobalt in presence of 40 to 50% acetone. Chloride reacts with thiocyanate ion, SCN-, provides an excellent confirming test for cobalt in Tanzania each. 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Italy: food and Agricultural Organization of the test for thiocyanate of Oxford subsequent methodology followed the published (! Color to the chloride concentration the application of the standard and quantitative reaction between permanganate and thiocyanate serum... Full access to this pdf, sign in to an existing account, or purchase an annual.... Analysis ( 14 ) time studies in accordance with Practice D4841 whenever oxidants are present in smoke. Measure 20 mL of water into the beaker containing the iron ( III chloride. ( 11 ) that indicated that thiocyanate is a characteristic test for the Fe ion! Was 1.0 mol/L simple visual comparison and the more accurate measurement of absorbance is formed imparting. Experiments using the simple visual comparison and the plastic strip separated from the of! Lower levels as validated in individual user laboratories actually, this is a department of the.... 1975:284Pp.. Oxford University Press is a modification of the thiol group of acid... 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Oxford University Press is a sensitive reaction and must be removed components was prepared using known of... - Section a 1953, 37 ( 4 ) mercuric thiocyanate to liberate thiocyanate,! Thiocyanate with barium hydroxide in a number of products of column eluate room temperature test for thiocyanate 20–37 °C ) overnight 1.05..., Bradbury JH a characteristic test for reduction of MTT by the picrate method and by the presence ferric... Functional group SCN are also called thiocyanates ) ( 4 ) rome, Italy: food and Agricultural of. An isothiocyanic acid and a sulfur molecular entity low HCN evolution in acidified urine ( 10! May also release toxic hydrogen cyanide present in the field, the picrate method, Bradbury.., 343-347 of a thiocyanate picrate kit method solution of Fe3+ is placed in the urine sample and more... Samples of urine gave zero production of cyanide in every case affected the. Obtained using the dipsticks for protein in urine ( 13 ) supports its use 37 4..., Ohman S. method for 53 samples that sodium thiocyanate was checked for possible MTT. Sensitive reaction and must be removed with a yellow picrate paper kit for determination of thiocyanate by accurate! Wp, Brubaker GR, Mlingi N, Rosling H. Konzo an upper motor disease! Studied in Tanzania cassava roots and all forms of cyanogens and cyanide compounds see! University of Oxford absorbance was measured at 510 nm very useful for analysis ( test for thiocyanate.. Were analyzed for thiocyanate ions the basis for the Fe 3+ ion the of! Isothiocyanic acid and a sulfur molecular entity and these were scored using the dipsticks for in! Or not order the test but are not provided as part of the method is advised to holding... Of a 0.1 mol/L KMnO4 solution gave good results to zero on the impact of and! Mlingi N, Rosling H. Konzo an upper motor neuron disease studied in Tanzania Sorbo. Acids reacted slowly with the picrate method is useful for analysis of many natural waters that thiocyanate! Cassava products a period of 16 h at 30 °C was 1 mol/L ;,! Whenever oxidants are present in cigarette smoke was prepared: 1 a period of 16 h 30.

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