Nitroprusside test

Note cautiously the characteristic odour of acetaldehyde which this solution possesses. Then with the solution carry out the following general tests for aldehydes described on p. 341 Test No. I (SchiflF s reagent). No. 3 (Action of sodium hydroxide). No. 4 (Reduction of ammoniacal silver nitrate). Finally perform the two special tests for acetaldehyde given on p. 344 (Nitroprusside test and the Iodoform reaction). 

Gives some of the tests for acetaldehyde, but more feebly e.g., it restores the colour to SchifF s reagent, gives a yellow resin with NaOH, and responds to the nitroprusside test. With ammoniacal AgN03, it gives a silver minor only after 2 -3 minutes warming. It does not give the iodoform reaction. 

Alcoholics can also develop ketoaddosis. In alcoholic ketoacidosis, 3-hydroxybutyrate is the major ketone body produced because there is usually a high NADH/NAD ratio in the hver. The urinary nitroprusside test detects only acetoacetate and may dramatically underestimate the extent of ketosis in an alcoholic. 3-Hydroxybutyrate levels (P-hydroxybutyrate) should always be measured in these patients. 

The cyanide nitroprusside test determines the presence of free sulfhydryl or disulfide compounds in urine samples [1, 3,4]. During the first step of the assay, cyanide reduces any disulfides that are present to free sulfhydryl compounds. In the second step, a reddish color reaction results when the free sulfhydryl groups complex with nitroprusside. A positive result is most usually due to cystine in the urine. Familial cystinuria is among the most common aminoacidurias. Disulfides are also excreted in other metabolic disorders such as homo cystinuria and ji-m e reap lol ac la le - cy s lei ne disulfiduria. Both will also produce positive results according to the following reaction RSH + Na2Fe(CN)5NO (sodium nitroprusside) — chromophore + NO. 

DSniges mercuric sulfate test, described in Refs 2 19 b)Dinitrophenylhydrazine test, described in Refs 10 19 and C/The Faugbt sodium nitroprusside test, described in Ref 16, p 685 (see also Ref 12)... 

SrS04. White. Sulphate present. Confirm by fusion with Na2C03 and apply sodium nitroprusside test. Contains sulphurous acid. Add a few drops of a dilute solution of iodine the latter is decolourized.t Sulphite present. ... 

Sulphide, (i) Dilute H2S04 on solid, and action of H2S on lead or cadmium acetate paper (IV.6, 1). (ii) Sodium nitroprusside test (IV.6, 6). 

Cool to 20 C, add to each liter 40 gm iodoacetic acid in 150 ml water adjusted to pH 7 to give pH 9 in mixture stand until nitroprusside test is negative. Add sufficient thioglycolate to give positive nitroprusside reaction. Dialyze against tap water. Then either... 

Although quantitative determination of individual ketone bodies is possible, these methods are not used as routine tests. The semiquantitative Acetest and Ketostix (Ames Co.) are frequently used but are insensitive to p-hydroxybutyrate. It is important to bear in mind, therefore, that a negative nitroprusside test result does not rule out ketoacidosis. (Note Details of the following tests are found on the Evolve site that accompanies this book.)... 

Ketostix is a modification of the nitroprusside test in which a reagent strip is used instead of a tablet. The Ketostix test gives a positive reaction within 15 seconds with a specimen containing at least 50 mg of acetoacetate per L. The accompanying color chart gives readings for ketone concentrations of 50,150, 400, 800, and 1600 mg/L. Acetone also reacts, but the test is less sensitive to it. 

M6. Middleton, J. E., A simple, safe nitroprusside test using ketostix reagent strips for detecting cystine and homocystine in urine. J. Clin. Pathol. 23, 90-91 (1970). 

A false positive urine ketone test can also occur with captopril when using the alkaline-nitroprusside test (Ketodiastix), which may affect the monitoring of diabetic control. ... 

Two common qualitative tests for amines are the Hinsberg test and the nitrous acid test. The nitrous acid test is not included here because the N-nitroso derivatives of some secondary amines are carcinogenic. The risk of producing an as-yet-unrecognized carcinogenic material in this procedure outweighs any possible benefit of a test that can also be misleading and difficult to interpret. The modified sodium nitroprusside test has been included as an alternative. 

E. Racker There is further evidence lactoyl glutathione gives a negative nitro-prusside test and a positive hydroxylamine test. The nitroprusside test becomes positive on alkaline hydrolysis of the ester and the hydroxamic test becomes negative. 

E. Racker We have done very little work on this. All we can say at this time is that in the presence of crude enzyme from liver and reduced DPN addition of insulin gives rise to SH groups as determined by the nitroprusside test. The enzyme is not very active. 

Others have compared nondividing cells with dividing cells with the aid of the nitroprusside test, and in a good many cases an increase in stainable SH associated with the actual division process was reported (15, 20, 21, 22). There is no need to review this earlier cytochemical literature in detail. 

Sodium nitroprusside test Spot plate Spot test... 

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