A Reliable Total Nitrogen Determination on Plant Tissue Accumulating Nitrate Nitrogen 1

1964 ◽  
Vol 56 (1) ◽  
pp. 89-90 ◽  
Author(s):  
L. A. Peterson ◽  
G. Chesters
Keyword(s):  
Total Nitrogen ◽  
Plant Tissue ◽  
Nitrate Nitrogen ◽  
Nitrogen Determination

Estimation of nitric nitrogen and total nitrogen in plant tissue extracts

1923 ◽  
Vol 13 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Patrick Hugh Gallagher
Keyword(s):  
Sulphuric Acid ◽  
Total Nitrogen ◽  
Plant Extracts ◽  
Plant Tissue ◽  
Nitrate Nitrogen ◽  
Reducing Agents ◽  
Amino Groups ◽  
Tissue Extracts ◽  
Colloidal Matter ◽  
Nitric Nitrogen

Several methods for estimating nitrates by reduction to ammonia were examined. The error involved in the use of acid reducing agents in presence of amino groups was emphasised.A method based on the use of Devarda's alloy and magnesia is recommended.In the estimation of nitrates in plant extracts, etc., by this method an equal volume of rectified spirit is first added to the solution to precipitate colloidal matter. The precipitate is filtered off and an aliquot part of the filtrate containing the equivalent in nitrate nitrogen of about 0.1 gm. of KNO3 is distilled with steam for 45 minutes with 1 gm. of Devarda's alloy and ½ gm. of freshly ignited magnesia. A blank determination is essential, in which the same volume of filtrate is distilled for the same length of time with ½ gm. of magnesia.In Kjeldahl estimations in presence of nitrates, where the separate estimation of nitrates is not required, 2 c.c. of 25 per cent. NaOH may be substituted for the magnesia. Relatively this is very much less soda than Devarda recommends. The mixture in this case may be distilled directly for half-an-hour. The nitrates are thus reduced and the ammonia produced is collected before beginning the digestion with sulphuric acid.This work was carried out under the supervision of Mr F. W. Foreman to whom the author's best thanks are due for much valuable criticism and advice.

Influence of the Initial Nitrogen Concentration on Eliminating Nitrogen Load of Europhia Sediment Capping with Active Barrier System (ABS)

2011 ◽  
Vol 374-377 ◽  
pp. 498-503
Author(s):  
Jin Lan Xu ◽  
Lei Wang ◽  
Jun Chen Kang ◽  
Ting Lin Huang ◽  
Yu Hua Dong
Keyword(s):  
Total Nitrogen ◽  
Nitrate Nitrogen ◽  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Overlying Water ◽  
Sediment Capping ◽  
Time Treatment ◽  
Total Nitrogen Concentration ◽  
Long Time ◽  
Active Barrier

Abstract: Active barrier system (ABS) capping zeolite with large surface area and strong adsorption ability is an effective way to control eutrophication of lake since it can remove ammonia in the lake released by sediment. Influence of the initial nitrogen concentration on eliminating nitrogen load of europhia sediment capping with active barrier system (ABS) were studied through an investigation of the repairment results of serious pollution period (total nitrogen concentration up to 25.33 mg/L), moderate pollution period (14.39 mg/L) and the slight pollution period (3.47 mg/L) of the ancient Canal of Yangzhou. The results showed that: (1) zeolite F1 inhibition effect is stronger than zeolite F2. More TN were removed as the initial TN concentration increased and longer rapid inhibit period were presented with the increased initial TN concentration. (2) The ammonia nitrogen in sediment could be rapidly released into the overlying water, and with lower initial TN concentration in source water, more ammonia would be released from the sediment. Long time treatment was necessary to inhibit the release of ammonia completely if the water showed a high initial TN concentration. (3) After covering zeolite, the total nitrogen in the overlying water were removed mainly through nitrification and denitrification. At the initial TN concentration of 3.47 mg/L, 14.39 mg/L, 25.88 mg/L, 61%, 45% and 52% of TN were removed by the conversion of ammonia to nitrogen gas, however, others left in water as nitrate nitrogen and nitrite residues, and 90% was nitrate nitrogen.

RELATIONSHIP OF YIELD AND TOTAL NITROGEN UPTAKE OF BRUSSELS SPROUTS PLANTS GROWN IN THE GREENHOUSE TO AVAILABLE SOIL NITROGEN

1969 ◽  
Vol 49 (3) ◽  
pp. 313-318 ◽  
Author(s):  
D. C. Munro
Keyword(s):  
Total Nitrogen ◽  
Soil Nitrogen ◽  
Nitrogen Uptake ◽  
Nitrate Nitrogen ◽  
Soil Samples ◽  
Moist Soil ◽  
Available Nitrogen ◽  
Air Drying ◽  
Brussels Sprouts ◽  
Relationship Of

Initial nitrate-nitrogen content of the soil gave a correlation coefficient (r) of 0.93 with yields and with total nitrogen uptake of Brussels sprouts plants (Brassica oleracea var. gemmifera DC., Jade Cross). Soil nitrogen extracted with 0.01 M NaHCO3 gave r values of 0.76 with yields and 0.75 with nitrogen uptake. Nitrate incubation results from leached, moist soil samples gave r values of 0.59 with yields and 0.56 with nitrogen uptake. However, air-drying of soil samples prior to leaching and incubation resulted in r values of only 0.15 and 0.11 with yields and nitrogen uptake, respectively. Available nitrogen determined by incubation without previous leaching of the soil samples gave high r values because of the influence of the initial nitrate nitrogen in the soil.

Total Nitrogen Determination of Various Sample Types: A Comparison of the Hach, Kjeltec, and Kjeldahl Methods

1987 ◽  
Vol 70 (3) ◽  
pp. 410-412
Author(s):  
Kevin L Watkins ◽  
Trygve L Veum ◽  
Gary F Krause
Keyword(s):  
Total Nitrogen ◽  
Sample Type ◽  
N Content ◽  
Nitrogen Determination ◽  
N Sources ◽  
Wide Range ◽  
Determination Methods ◽  
The Mean ◽  
Intermediate Results

Abstract Conventional Kjeldahl analysis with modifications, Kjeltec analysis with block digestion and semiautomated distillation, and the Hach method for determining nitrogen (N) were compared using a wide range of samples. Twenty different sample types were ground and mixed. Each sample type was divided into 5 subsamples which were analyzed for N by each of the 3 methods. In each sample type, differences (P < 0.05) were detected among the 3 N determination methods in 5 of the 20 N sources analyzed. The mean N content over all 20 samples was higher with Kjeldahl analysis (P < 0.05) than with Kjeltec, while Hach analysis produced intermediate results. Results also indicated that the Hach procedure had the greatest ability to detect differences in N content among sample types, being more sensitive than either other method (P < 0.05).

Runoff characteristics of nutrients in the forest streams in Hyogo Prefecture, Japan

2001 ◽  
Vol 44 (7) ◽  
pp. 151-156 ◽  
Author(s):  
S. Umemoto ◽  
Y. Komai ◽  
T. Inoue
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Suspended Solids ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Stream Flows ◽  
The Difference ◽  
Hyogo Prefecture ◽  
Forest Streams ◽  
Precipitation Events

Nutrients and other pollutant runoffs from streams in artificial forest areas in central Hyogo Prefecture in southwest Japan have been investigated to estimate pollutant loads since 1995. The orthophosphate and ammonium nitrogen contents were usually low and constant during the investigation. When the flowrates of the streams were normal, the concentrations of suspended solids, CODMn, TOC and total phosphorus were very low, and did not change much. However, when stream flows were increased by rainstorms or other precipitation, higher concentrations of these parameters occurred. Otherwise, the average concentrations of nitrate nitrogen and total nitrogen were 0.26 mg/l and 0.31 mg/l, respectively, and they were often increased by precipitation events. They changed at the same time because the ratio of nitrate nitrogen per total nitrogen was high, about 80%. The fluctuation of concentrations of total phosphorus was similar to SS concentrations, which suggested that phosphorus was discharged in the types of suspended solids from forest areas. The specific loads of the nutrients and some other pollutants did not differ among the three watersheds investigated. However, the difference among them between fine days and rainy days was fairly large. It was presumed that pollutant runoff from forest areas is strongly dependent on precipitation events.

Direct and Indirect Determination of True Protein Content of Milk by Kjeldahl Analysis: Collaborative Study

1991 ◽  
Vol 74 (2) ◽  
pp. 281-288 ◽  
Author(s):  
David M Barbano ◽  
Joanna M Lynch ◽  
J Richard Fleming
Keyword(s):  
Nitrogen Content ◽  
Protein Content ◽  
Total Nitrogen ◽  
Collaborative Study ◽  
Total Nitrogen Content ◽  
Nonprotein Nitrogen ◽  
Protein Nitrogen ◽  
Nitrogen Determination ◽  
True Protein

Abstract Currently, the reference procedure for determination of the "protein" content of milk is based on measurement of the total nitrogen content of milk by the Kjeldahl method (AOAC method, 920.105). About 6% of the total nitrogen content of milk Is nonprotein nitrogen. Therefore, total nitrogen multiplied by the conversion factor 6.38 overestimates the true protein content of milk on average by about 6%. In the present study, new direct and Indirect methods were developed for measurement of the true protein content of whole milk by Kjeldahl nitrogen determination. Both new methods are sample preparation procedures used to fractionate the nitrogen-containing compounds In milk prior to measurement of the nitrogen content of these fractions by Kjeldahl analysis. The collaborative study consisted of 9 pairs of blind duplicate milk samples that were analyzed for total nitrogen, nonprotein nitrogen, and protein nitrogen by each of 10 laboratories. Both methods for true protein measurement (direct and Indirect) gave acceptable statistical performance characteristics and good agreement between methods. The new direct method requires about half the laboratory analysis work of the indirect method (i.e., total minus nonprotein nitrogen). The methods have been adopted official first action by AOAC as (1) a new method for nonprotein nitrogen determination in milk, (2) a new method (direct) for determination of protein nitrogen content of milk, and {3) an alternative method (indirect) for determination of protein nitrogen content of milk.

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