Nitrite Test Research Articles

Colorimetric Methods for the Quantitative Estimation of Indole(3)Acetic Acid

1. Several colorimetric methods were studied to determine their applicability for the quantitative measurement of indoleacetic acid in water solution. These included the reaction between indoleacetic acid and (1) potassium nitrite and nitric acid; (2) ferric chloride and sulphuric acid; and (3) ferric chloride and hydrochloric acid. The nitrite and the ferric chloride-sulphuric acid tests were investigated in detail in order to determine the effect of the different factors involved upon the intensity and stability of the color produced. 2. The nitrite test proved to be applicable for the determination of indoleacetic acid in aqueous solutions having a range of concentrations from 0.01 to 0.15 mg. per cubic centimeter; the ferric chloride-sulphuric acid test was suitable for the estimation of total amounts of from 0.02 to 0.1 mg., under the conditions described. The ferric chloride-hydrochloric acid test was sensitive to essentially the same range of concentrations as that of the nitrite test, but was less suitable as the color produced was not stable.

UNUSUAL REACTIONS OF PATIENTS WITH HYPERTENSION TO GLYCERYL TRINITRATE

Hypertension has long intrigued physicians. Arteriosclerosis, a condition commonly associated with hypertension, has been extensively and profitably studied both clinically and pathologically. Histologic studies of patients with hypertension, however, have yielded but little information concerning the mechanism of this malady. The few anatomic changes that do occur are usually ascribed to the changes secondary to elevation of the blood pressure. It might be better to consider hypertension as a kinetic or an altered physiologic expression of a diseased condition. Experiments illustrating altered or abnormal responses to a known or standard stimulus might then give some insight into this changed vascular state. Following this line of reasoning, studies were begun. First a standard procedure or test was necessary. The amyl nitrite test of Stieglitz 1 appeared to fulfil the requirements, and it was tried. A small pearl of amyl nitrite (0.3 cc.) was crushed in a towel and held directly under

THE NITRATE REDUCTION TEST AND ITS SIGNIFICANCE IN THE DETECTION OF BACILLUS LARVAE

Bacillus larvae differs from most nitrate-reducing species in its ability to accumulate nitrite in nutrient solutions containing but small amounts of nitrate (0.001%). Most nitrate-reducing organisms show no accumulation of nitrite at this concentration owing to assimilation of nitrate or disappearance of nitrite through reduction or assimilation. With many nitrate-reducing bacteria disappearance of nitrite keeps pace with nitrite formation only up to a certain concentration, varying with the organism, above which nitrite may accumulate.The ability of B. larvae to accumulate nitrite in semi-solid carrot or turnip extract media with no added nitrate is of considerable aid in the cultural test for this organism. Of five other organisms concerned with brood disease or occurring as contaminants in comb, which were grown in association with B. larvae, none showed interference with accumulation of nitrite by the latter except B. orpheus. With this species a positive nitrite test was dependent on the relative development of the organisms, B. larvae exerting a certain antagonistic action. None of the eight species of bacteria tested prevented recognition of growth of B. larvae in the semi-solid medium.

GRADUATED JUGULAR COMPRESSION IN THE LUMBAR MANOMETRIC TEST FOR SPINAL SUBARACHNOID BLOCK

The lumbar manometric test is a routine procedure whenever disease of the spinal cord is suspected. Stookey, Merwarth and Frantz1and Stookey and Klenke2have standardized the original test of Queckenstedt by introducing new procedures in it, greatly increasing its value. Their contributions consisted in adding touch compression of the jugular veins, timing and charting the rise and fall of pressure after firm jugular compression, and finally in emphasizing the value of Ayala's index, or what they called the pressure index. Attention to a host of details which modify the pressure readings is still required, and the chief source of error is concerned with the maneuvers incident to manual jugular compression. Elsberg and Hare3introduced the amyl nitrite test for spinal subarachnoid block, because of the disadvantages of manual jugular compression. The amount of pressure on the jugular veins that is often necessary may cause the patient

Absorption of Nitrite After the Oral Ingestion of Bismuth Subnitrate

Stieglitz advocated the use of bismuth subnitrate in the treatment of hypertension. He suggested that the nitrate was partially reduced in the intestine and that the absorbed nitrite was responsible for the desired therapeutic action. In the majority of cases, nitrite was found in the urine. Ayman recently reported that the drug had no demonstrable effect on the blood pressure. Several cases of nitrite poisoning following ingestion of bismuth subnitrate have been reported., In most cases, large quantities had been given for x-ray examination to patients with open intestinal lesions or hypersensitive mucosae. If bismuth subnitrate is partially decomposed with absorption of nitrite, the absorption of some bismuth might be expected. The metal has been reported in the tissues and urine following ingestion of the subcarbonate. It was planned to study the urinary excretion of bismuth, nitrate and nitrite in normal individuals receiving the amount of the subnitrate recommended by Stieglitz. The diet was not rigidly controlled, although variation from day to day was not great. Corned meats and large amounts of vegetables were avoided. 0.5 gm. of the drug was taken 3 times a day for a month. At the end of the period a purge of magnesium citrate cleared the intestinal tract as quickly and thoroughly as possible, and a short after-period was run. Bismuth determinations were made by the method of Leonard, nitrates after Whalen, and qualitative nitrite tests by the Gries (as modified by Hyman and Mann) and Fearon procedures. Within 2 days of the start of the bismuth subnitrate ingestion, the urinary nitrate nitrogen increased from 4.9 mg. to 57.8 mg. in 24 hours, or over 1000%, and remained at about 800% of the normal during the drug period.

The Use of the Nitrite Test in Determining the Source of Pollution of a Water Supply

The Use of the Nitrite Test in Determining the Source of Pollution of a Water Supply