Collaborative Studies on Methods for Nitrate and Nitrite in Meat

1964 ◽  
Vol 47 (2) ◽  
pp. 395-399
Author(s):  
W A Landmann ◽  
M C Worland
Keyword(s):  
Colorimetric Method ◽  
High Standard ◽  
Systematic Errors ◽  
Random Errors ◽  
Griess Reagent ◽  
High Standard Deviation ◽  
Color Development ◽  
Collaborative Studies ◽  
Nitrate And Nitrite ◽  
Colorimetric Procedure

Abstract Results of collaborative studies on three nitrate and two nitrite methods were examined by statistical procedures of Youden. The FeCl2 procedure was again found lo be subject to extreme bias. A modified procedure employing m-xylenol gave results which were somewhat improved in precision over previous tests. However, the procedure was still subject to systematic errors and rather large random errors resulting in only fair precision. A direct nitrate method based on color development with brucine was highly variable and unsatisfactory. The colorimetric procedure for nitrite, using Griess reagent, appeared to be relatively free of bias, but had only fair precision, and its usefulness is limited by the high standard deviation. An iodometric procedure, based on liberation of iodine from KI solution by the nitrite and titration with thiosulfate, proved to be quite precise and subject only to small bias, within acceptable limits of procedure. This method was far superior to the colorimetric method and should be adopted as official, first action for dry cure mix and pickle mix.

Improved Colorimetric Method for Determining Nitrate and Nitrite in Foods

1978 ◽  
Vol 61 (6) ◽  
pp. 1389-1394 ◽  
Author(s):  
Nrisinha P Sen ◽  
Barbara Donaldson
Keyword(s):  
Nitrate Concentration ◽  
Colorimetric Method ◽  
Meat Products ◽  
Sulfanilic Acid ◽  
Griess Reagent ◽  
Color Development ◽  
Constant Ph ◽  
Cured Meat ◽  
The Difference ◽  
Nitrate And Nitrite

Abstract A method is described for determining nitrate and nitrite in cured meat products, cheeses, and vegetables. The nitrite is determined colorimetrically by diazotization of sulfanilic acid and subsequent coupling with N-(l-naphthyl)-ethylenediamine. The concentration of nitrate plus nitrite is determined similarly but after reduction of the nitrate to nitrite on a cadmium column. The difference of the 2 values is a measure of the nitrate concentration. The main improvements are replacing the Griess reagent, which contains a carcinogen, with a mixture of sulfanilic acid and N-(l-naphthyl)- ethylenediamine, providing for adjustment of pH of the sample suspension during extraction and digestion by heating, and maintaining constant pH by controlled addition of buffers and acids during color development. The method was successfully applied to the analysis of 15 samples of meat products, 23 cheeses, and 6 different vegetables. The average recovery of sodium nitrite added at levels ranging from 10 to 30 ppm was 9 5% and recovery of sodium nitrate added at levels from 30 to 400 ppm was 9 4% (corrected for cadmium column efficiency).

scholarly journals Antioxidant Properties of a Parsley (Petroselinum crispum) Juice Rich in Polyphenols and Nitrites

2016 ◽  
Vol 4 (Special-Issue-October) ◽  
pp. 114-118
Author(s):  
Camelia Papuc ◽  
Corina Predescu ◽  
Valentin Nicorescu ◽  
Georgeta Stefan ◽  
Isabela Nicorescu
Keyword(s):  
Antioxidant Activity ◽  
Colorimetric Method ◽  
Antioxidant Properties ◽  
Enzymatic Reaction ◽  
Reducing Power ◽  
Transition Metal Ions ◽  
Aluminium Chloride ◽  
Petroselinum Crispum ◽  
Griess Reagent ◽  
Nitrate And Nitrite

Parsley (Petroselinum crispum) is an herbaceous vegetable used as foodstuff, spice and medicinal plant because it provides antioxidants especially flavonoids (apigenin), vitamins (K, C and A), and volatile oils, among other compounds. Because parsley has important concentrations of nitrates and flavonoids, very little vegetal pigment and a mild flavour profile, it was chosen for this study. The aim of this study was to obtain parsley juice rich in nitrite and polyphenols and to assess its antioxidant activity. To obtain nitrite from nitrate by enzymatic reaction, Staphylococcus xylosus ATCC 29971 was used as nitrate reductase source. To obtain the vegetable juice, fresh roots were minced and homogenized in aqueous solution. The sterile juice was filtered and then inoculated with S. xylosus and incubated at 37°C. The nitrate and nitrite concentrations (mg/L) were determined using a colorimetric method using salicylic acid and Griess reagent, respectively. The total polyphenols content (TPC) was measured with Folin-Ciocalteu reagent and expressed as mg gallic acid equivalent / 100 mL (mg GAE / 100 mL). The total flavonoids content (TFC) was measured with aluminium chloride reagent, and expressed as mg catechin equivalent / 100 mL (mg CE / 100 mL). To determine the antioxidant activity of parsley juice, the ability to reduce DPPH synthetic radical, reducing power of Fe3+ ion and the capacity of chelating transition metal ions were assessed. Maximum concentration of nitrites was achieved for parsley juice in the presence of S. xylosus after 24 hours; TPC was 14.87 mg GAE / 100 mL and TFC was 11.21 mg CE / 100 mL. The ability of parsley fermented juice to reduce DPPH synthetic radical was 79.45%, while the capacity to reduce Fe3+ was 0.758 ± 0.14 (absorbance at 700 nm) and to chelate Fe2+ ion was 23.64%. Parsley juice represents an important source of natural nitrate and flavonoids, with important antioxidant capacity.

Statistics and parallaxes

1978 ◽  
Vol 48 ◽  
pp. 7-29
Author(s):  
T. E. Lutz
Keyword(s):  
Experimental Design ◽  
Statistical Methods ◽  
Review Paper ◽  
Systematic Errors ◽  
Past Experience ◽  
Random Errors ◽  
Trigonometric Parallaxes ◽  
Systematic And Random Errors

This review paper deals with the use of statistical methods to evaluate systematic and random errors associated with trigonometric parallaxes. First, systematic errors which arise when using trigonometric parallaxes to calibrate luminosity systems are discussed. Next, determination of the external errors of parallax measurement are reviewed. Observatory corrections are discussed. Schilt’s point, that as the causes of these systematic differences between observatories are not known the computed corrections can not be applied appropriately, is emphasized. However, modern parallax work is sufficiently accurate that it is necessary to determine observatory corrections if full use is to be made of the potential precision of the data. To this end, it is suggested that a prior experimental design is required. Past experience has shown that accidental overlap of observing programs will not suffice to determine observatory corrections which are meaningful.

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

Establishing inherent uncertainty in the shifts determined by volumetric imaging

2017 ◽  
Vol 16 (3) ◽  
pp. 258-264
Author(s):  
Upendra Kumar Giri ◽  
Anirudh Pradhan
Keyword(s):  
Linear Accelerator ◽  
Systematic Errors ◽  
Cone Beam ◽  
Random Errors ◽  
Mean Values ◽  
Volumetric Imaging ◽  
X Ray ◽  
Image Quality Control ◽  
The Mean ◽  
Six Degree Of Freedom

AbstractObjectiveThis study was conducted for establishing inherent uncertainty in the shift determination by X-ray volumetric imaging (XVI) and calculating margins due to this inherent uncertainty using van Herk formula.Material and methodsThe study was performed on the XVI which was cone-beam computed tomography integrated with the Elekta AxesseTM linear accelerator machine having six degree of freedom enabled HexaPOD couch. Penta-Guide phantom was used for inherent translational and rotational shift determination by repeated imaging. The process was repeated 20 times a day without moving the phantom for 30 consecutive working days. The measured shifts were used for margins calculation using van Herk formula.ResultsThe mean standard deviations were calculated as 0·05, 0·05, 0·06 mm in the three translational (x, y and z) and 0·05°, 0·05°, 0·05° in the three rotational axes (about x, y, z). Paired sample t-test was performed between the mean values of translational shifts (x, y, z) and rotational shifts. The systematic errors were found to be 0·03, 0·04 and 0·03 mm while the random errors were 0·05, 0·06 and 0·06 mm in the lateral, cranio-caudal and anterio-posterior directions, respectively. For the rotational shifts, the systematic errors were 0·02, 0·03 and 0·03 and the random errors were 0·06, 0·05 and 0·05 in the pitch, roll and yaw directions, respectively.ConclusionOur study concluded that there was an inherent uncertainty associated with the XVI tools, on the basis of these six-dimensional shifts, margins were calculated and recorded as a baseline for the quality assurance (QA) programme for XVI imaging tools by checking its reproducibility once in a year or after any major maintenance in hardware or upgradation in software. Although the shift determined was of the order of submillimetre order, still that shift had great significance for the image quality control of the XVI tools. Every departments practicing quality radiotherapy with such imaging tools should establish their own baseline value of inherent shifts and margins during the commissioning and must use an important QA protocol for the tools.

Collaborative Study on Assay of Sulfur Dioxide in Dried Fruit

1965 ◽  
Vol 48 (4) ◽  
pp. 796-801
Author(s):  
F S Nury ◽  
H R Bolin
Keyword(s):  
Sulfur Dioxide ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Dried Fruits ◽  
Dried Fruit ◽  
Test Materials ◽  
Colorimetric Procedure ◽  
Satisfactory Recovery

Abstract Sulfur dioxide analysis by official (Monier-Williams) methods was compared with a new colorimetric procedure for dried fruits. Dried peaches, pears, apples and golden raisins were the test materials. The colorimetric method was found to be neither more nor less variable than two official methods except in analysis of dried pears, took less time and was easier to perform than the official methods, and yielded satisfactory recovery of sulfur dioxide.

scholarly journals STUDI PERAMBATAN KESALAHAN SISTEMATIS LUAS LAHAN PARKIR KAMPUS MENGGUNAKAN PENDEKATAN LUAS SEGITIGA SEMBARANG

2019 ◽  
Vol 13 (1) ◽  
pp. 14
Author(s):  
Hendro Supratikno ◽  
David Premana
Keyword(s):  
Systematic Error ◽  
Error Propagation ◽  
Measurement Data ◽  
Systematic Errors ◽  
Random Errors ◽  
Land Area ◽  
Parking Lots ◽  
Parking Lot ◽  
Data Error ◽  
Definition Of

Parking is a condition of not moving a vehicle that is temporary because it was abandoned by the driver. Included in the definition of parking is every vehicle that stops at certain places whether stated by traffic signs or not, and not solely for the benefit of raising and / or lowering people and / or goods.Campus 3 Lumajang State Community Academy has facilities and infrastructure prepared by the Lumajang Regency government. However, the parking lots provided cannot accommodate vehicles optimally because of the ratio of the number of vehicles and the area of the parking area that is not appropriate. This is because the area of the parking lot is not analyzed by data error when measuring.Each measurement data is assumed to have errors both systematic errors, random errors, and large errors (blunders), so that in the measurement of parking lots certainly there are errors. From this the authors intend to conduct research to find out how the propagation of systematic errors and the large systematic errors of the area of campus parking lot 3 Lumajang Community Academy.The methods used in this study include preparing materials and tools, making land sketches, decomposing them, determining distances using theodolite, determining land area equations, and finding systematic error propagation. So that the final goal in this study is to find large systematic errors in the parking area of Campus 3 of the Lumajang State Community Academy

scholarly journals Calculating Point Cloud Object Volume Using Co-Opposite-Direction Slicing Method

2019 ◽  
Author(s):  
Bin Li ◽  
Xiaowei Bi ◽  
Cheng Peng ◽  
Yong Chen ◽  
Xiaofa Zhao ◽  
...  
Keyword(s):  
Full Advantage ◽  
Opposite Direction ◽  
Point Cloud ◽  
Systematic Errors ◽  
Random Errors ◽  
Improved Method ◽  
Cone Model ◽  
Slicing Method

Although the Slicing Method (SM) is effective for calculating the volume of point cloud objects (PCOs), it is restricted in terms of applicability and practicability because of a certain contingency and directional defects. The Co-Opposite-Direction Slicing Method (CODSM) proposed in this paper is an improved method for calculating PCO volume by increasing parallel (co-opposite-direction) observation and considering the two-way mean as the result. This method takes full advantage of the mutual offsetting of random errors and the compensation of systematic directional errors, which can effectively overcome (or mitigate) the effect of random errors and reduce the effect of systematic errors in SM. In this paper, two typical objects, a cone model and a stone lion base, are the examples for calculating PCO volume using CODSM. The results show that CODSM has all the inherent advantages of SM and effectively weakens the volatility of random errors and the directionality of systematic errors from SM. Therefore, CODSM is a robust configuration upgrade of SM.

Two Fiber Optical Fiber Thermometry

2000 ◽  
Author(s):  
Matthew R. Jones ◽  
Jeffery T. Farmer ◽  
Shawn P. Breeding
Keyword(s):  
Optical Fiber ◽  
Elevated Temperatures ◽  
Systematic Errors ◽  
Radiative Flux ◽  
Metallic Coating ◽  
Temperature Measurements ◽  
Single Fiber ◽  
Random Errors ◽  
Fiber Optical

Abstract An optical fiber thermometer consists of an optical fiber whose sensing tip is given a metallic coating. The sensing tip of the fiber forms an isothermal cavity, and the emission from this cavity is approximately equal to the emission from a blackbody. Temperature readings are obtained by measuring the spectral radiative flux at the end of the fiber at two wavelengths. The ratio of these measurements is used to infer the temperature at the sensing tip. However, readings from optical fiber thermometers are corrupted by emission from the fiber when extended portions of the probe are exposed to elevated temperatures. This paper describes several ways in which the reading from a second fiber can be used to correct the corrupted temperature measurements. It is shown that two of the correction methods result in significant reductions in the systematic errors. However, these methods are sensitive to random errors, so it is preferable to use a single fiber OFT if the uncertainties in the measurements are large.

scholarly journals Youden Analysis of Karl Fischer Titration Data from an Interlaboratory Study Determining Water in Animal Feed, Grain, and Forage

2005 ◽  
Vol 88 (6) ◽  
pp. 1840-1841 ◽  
Author(s):  
Frank E Jones
Keyword(s):  
Animal Feed ◽  
Systematic Errors ◽  
Interlaboratory Study ◽  
Matched Pairs ◽  
Karl Fischer Titration ◽  
Karl Fischer ◽  
Collaborative Studies ◽  
Titration Data ◽  
Repeatability And Reproducibility

Abstract Data from a recent interlaboratory study of the determination of water (moisture) in animal feed, grain, and forage (plant tissue) by Karl Fischer titration were re-analyzed using Youden plots. The purpose was to show the unique ability these plots possess of separating random and systematic errors visually while providing numerical estimates of the precision and the systematic error of the method. Furthermore, the usefulness of the technique is underscored because AOAC INTERNATIONAL allows the use of matched pairs in collaborative studies to obtain estimates of repeatability and reproducibility.

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