摘要:
A Karl Fischer reagent useful in the determination of water, comprises sulfur dioxide, iodine and a salt which is a system compatible addition compound of a nitrogen-containing organic base having a pK.sub.b 2.
摘要:
The invention relates to an agent and a method for the dry chemical detection of lactoperoxidase in milk or dairy products. The method according to the invention is characterized by rapid execution thereof and said method has a high degree of sensitivity. The high detection sensitivity is achieved by adding iodide ions to the usual reagents.
摘要:
The invention relates to a dry chemical method and a test strip for determining calcium and magnesium in aqueous samples. Said test strip contains o-cresolphthalein complex (o-CPC; CAS Registry No. 2411-89-4) as a colour-causing reagent in a buffer system with a pH value of below 8.5. By using in particular an aqueous ethanolic imidazole buffer with a pH value of 6.75, conditions can be set up in such a way that the o-CPC has an identical molar sensitivity with respect to Ca and Mg. The total water hardness of aqueous samples can thus be easily determined.
摘要:
A Karl-Fischer reagent useful in a process for the determination of water contains a pyridine substitute, sulfur dioxide and iodine. As the pyridine substitute, the reagent contains at least one compound from the group comprising the guanidines, amidines, imido-esters, isoureas, cyanamide, or salts thereof with a weak organic acid.
摘要:
An essentially pyridine-free Karl Fischer reagent useful in the determination of water, comprises a dissolving agent containing sulfur dioxide and a pyridine substitute in a Karl Fischer solvent, and a titrating agent containing iodine in a Karl Fischer solvent, wherein the pyridine substitute is an alkali or alkaline earth metal benzoate or ammonia, and the reagent is essentially free of pyridine.
摘要:
The invention relates to a Karl-Fischer reagent, kit and a process for the determination of water with the aid of this reagent, which contains, instead of iodine, an approximately equimolar amount of iodine halides and salts of aromatic nitrogen-containing heterocyclic compounds.
摘要:
A pyridine-free Karl-Fischer reagent for the determination of water which comprises (a) a solvent solution containing sulfur dioxide and an amine in a Karl-Fischer reagent solvent, the amine being functionally equivalent to pyridine in a Karl-Fischer reagent, and (b) a titrating agent containing iodine in a Karl-Fischer solvent; the molar ratio of amine to sulfur dioxide being about 2:1 to about 1:1 and the reagent being essentially free of pyridine.
摘要:
A new Karl Fischer reagent contains as a pyridine substitute at least one compound of the general formula ##STR1## in which R.sup.1 and R.sup.2, which can be identical or different, =hydrogen or alkyl having 1-6 C atoms,R.sup.3 =alkyl having 1-6 C atoms,X=alkali metal ion or one equivalent of an alkaline earth metal ion,n=0 or a number from 1 to 4 andm=a number from 1 to 4.