scholarly journals Causes of failing the draft ANSI Standard N13. 30 radiobioassay performance criterion for minimum detectable amount

1990 ◽  
Author(s):  
J.A. MacLellan
Keyword(s):  
Performance Criterion ◽  
Detectable Amount ◽  
Minimum Detectable Amount

Advances And Enhancements in Light Element EDXRF

1987 ◽  
Vol 31 ◽  
pp. 449-454
Author(s):  
James R. Bogert
Keyword(s):  
Line Intensity ◽  
Light Element ◽  
Rate Of Change ◽  
Light Elements ◽  
Detectable Amount ◽  
X Ray ◽  
Wide Range ◽  
Minimum Detectable Amount ◽  
Excitation Conditions ◽  
System Geometry

One of the strongest analytical qualities of energy-dispersive x-ray fluorescence (EDXRF) is the wide range of analyte elements that can be detected and analyzed. Historically, the technique has covered all the elements from sodium (Z=11) and above. A useful measure of specific spectrometer performance is analyte sensitivity. X-ray spectrometric sensitivity is usually expressed in terms of minimum detectable amount of analyte or rate of change of analyte line intensity with change in amount of analyte. Many factors affect analyte sensitivity in EDXRF. These include excitation conditions, specimen conditions, system geometry, atmosphere, detector and readout conditions, and of course the specific analyte line. Typically, EDXRF sensitivity is very good, and low ppm concentrations of analytes are routinely analyzed–until one encounters the light elements.

Determination of Fumonisin B1 and B2 in Corn and Corn-Based Products in Turkey by High-Performance Liquid Chromatography

2001 ◽  
Vol 64 (7) ◽  
pp. 1072-1075 ◽  
Author(s):  
GÜLDEN Z. OMURTAG
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
High Performance ◽  
Fumonisin B1 ◽  
Turkish Population ◽  
Detectable Amount ◽  
Derivatives Of ◽  
Minimum Detectable Amount

The purpose of this study was to investigate fumonisin B1 (FB1)- and B2 (FB2)-contaminated corn and corn-based products consumed especially by the Turkish population. FB1 and FB2 were detected using high-performance liquid chromatography with fluorescence detection. The total number of commercially available corn and corn-based product samples analyzed in this research was 82. The recoveries were found to be 94.4 ± 4.62% and 86.5 ± 4.86% for cornmeal spiked with known amounts of FB1 and FB2 (1 ppm), respectively. The minimum detectable amount for the o-phthaldialdehyde derivatives of FB1 and FB2 were 1 ng and 5 ng, respectively. Detected levels of FB1 were between 0.25 ppm and 2.66 ppm in 25.6% of the samples, and detected level of FB2 in a single cornmeal sample was 0.55 ppm.

Biochemical Platelet Abnormalities After Renal Transplantation

1981 ◽  
Author(s):  
A Capitanio ◽  
P M Mannucci ◽  
C Ponticelli ◽  
F I Pareti
Keyword(s):  
Renal Transplantation ◽  
Plasma Levels ◽  
Serum Levels ◽  
Fibrinopeptide A ◽  
Detectable Amount ◽  
Renal Transplants ◽  
Minimum Detectable Amount ◽  
Normal Controls ◽  
Low Serum

In recipients of renal transplants (RT), the biochemical defects accompanying increased platelet (plt)deposition in the grafts and shortened survival in the circulation are poorly characterized. 48 patients (pts) with RT (13 acute transplant rejections, ATR; 15 chronic transplant rejections, CTR; and 18 normofunctioning transplants, NFT)had lower pit serotonin (5HT) and higher plasma beta-thromboglobulin (BTG)than normal controls(NC). These abnormalities were more pronounced in ATR than CTR (5HT : 0.13±0.10, 0.18±0.08 ng/108 pits, respectively; BTG: 85±37, 62±49 ng/ml), but were also present in NFT compared with NC (5HT : 0.27±0.08, 0. 34±0. 08; BTG ; 39±33, 16±7). RT recipients also had an abnormal production of ptl pro staglandins, as expressed by low serum levels of thromboxane B2 (ATR: 324±241 pmol/108 pits; CTR : 260 ±180; NFT:262±170; NC: 441±155). T×B2 attained measurable plasma levels in 4 CTR pts (range : 0.7-9. 7 pmol/ml), whereas it was below the minimum detectable amount ( 0.5pmol/ml) in the remaining pts. Plasma fibrinopeptide A (FPA) was higher in ATR than in NC (2.6±0.9 ng/ml; 1.5± 0.8, respectively); in CTR and NFT , FpA was not different than in NC (1.9±1.1; 1.4±0. 9).These findings suggest that in RT the in vivo occurrence of the pit release reaction has resulted in the extrusion of the content of cyt oplasmic organelles and the circulation of exhausted pits. The resulting abnormalities were usually proportional to the extent of graft injury,but were also present in NFT. Vasoactive, mitogenic and proaggregatory substances released from pits might damage the graft and aggravate the rejection process.

High Pressure Liquid Chromatographic Determination of Naphthaleneacetic Acid Residues in Apples

1979 ◽  
Vol 62 (1) ◽  
pp. 100-106
Author(s):  
William P Cochrane ◽  
Monique Lanouette
Keyword(s):  
High Pressure ◽  
Chromatographic Determination ◽  
Excitation Wavelength ◽  
Naphthaleneacetic Acid ◽  
Detectable Amount ◽  
High Pressure Liquid Chromatographic ◽  
Ultraviolet Detector ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Minimum Detectable Amount

Abstract An ion-suppression reverse phase high pressure liquid chromatographic method is described for determining naphthaleneacetic acid (NAA) residues in apples. Samples are extracted with acidic chloroform, filtered through pre-acidified Hy-Flo Supercel, and cleaned up by acid-base partitioning. The extract can be successfully chromatographed on either a μLiChrosorb NH2 or μBondapak C18 column and quantitated by using a variable wavelength ultraviolet detector set at 220 mn, The mobile phase is acetonitrile-water (20+80) buffered to pH 3.5 (μLiChrosorb column) or pH 5.2 (μBondapak column) and flowing at 1.0—2.0 ml/min. Recoveries ranged from 86 to 98%. The minimum detectable amount was 0.5 ng, which easily permitted the quantitation of 0.01 ppm NAA in 50 g sample. A fluorometric detector was 4 times as sensitive, using an excitation wavelength of 220 mm and monitoring the emission at 340 nm. For this detector, the minimum detectable amount was 0.12 ng NAA.

Testing Decision Level (DL) and Minimum Detectable Amount (MDA) for Hanford In Vivo Counting Systems

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Brett L. Rosenberg ◽  
Timothy P. Lynch ◽  
Cheryl L. Antonio
Keyword(s):  
Detectable Amount ◽  
Decision Level ◽  
Minimum Detectable Amount

Thin Layer Chromatographic Determination of Deoxynivalenol in Wheat and Corn

1984 ◽  
Vol 67 (1) ◽  
pp. 40-43 ◽  
Author(s):  
Mary W Trucksess ◽  
Stanley Nesheim ◽  
Robert M Eppley
Keyword(s):  
Thin Layer ◽  
Ethyl Acetate ◽  
Ultraviolet Light ◽  
Silica Gel ◽  
Steam Bath ◽  
Chromatographic Determination ◽  
Detectable Amount ◽  
Fluorescent Spot ◽  
Minimum Detectable Amount

Abstract A thin layer chromatographic (TLC) method for determining deoxynivalenol (DON) in corn and wheat was developed. DON is extracted from the grain with acetonitrile–water (84 + 16) and filtered through a column of mixed alumina–charcoal–Celite (0.5 g + 0.7 g + 0.3 g). The solvent is evaporated on a steam bath. Ethyl acetate is added to the residue and heated to dissolve DON. After cooling, the residue is transferred to a vial with additional ethyl acetate and is dissolved in CHCl3–acetonitrile (4 + 1) for TLC on an AlCl3-impregnated silica gel plate with CHCI3–acetone–isopropanol (8 + 1 + 1). The plate is heated in a 120°C oven for 7 min; a blue fluorescent spot is produced under longwave ultraviolet light. DON is quantitated visually and/or fluorodensitometrically by comparison with reference standards. The minimum detectable amount of DON is ca 20 ng/spot. The limit of DON determination is ca 40 ng/g for wheat and 100 ng/g for corn. Recoveries of DON added to wheat and corn at 100, 500, and 1000 ng/ g levels were 85, 93, and 88% and 77, 80, and 80%, respectively.

scholarly journals Determination of the Residues of Eleven Organophosphorus Insecticides in Job's-tears by Gas Chromatography with a Nitrogen-Phosphorus Detector

2004 ◽  
Vol 87 (5) ◽  
pp. 1260-1263 ◽  
Author(s):  
Jialun Wu ◽  
Liqing Li
Keyword(s):  
Gas Chromatography ◽  
Detectable Amount ◽  
Organophosphorus Insecticides ◽  
Chinese Herbal ◽  
Job’S Tears ◽  
Limit Of Quantitation ◽  
Nitrogen Phosphorus Detector ◽  
Minimum Detectable Amount ◽  
Nitrogen Phosphorus

Abstract A simplified method for determining 11 organophosphorus insecticides (dichlorvos, methamidophos, acephate, diazinon, dimethoate, chlorpyrifos, malathion, parathion, quinalphos, methidathion, and ethion) in the Chinese herbal medicine Job's-tears is described. Standards were fortified into Job's-tears (5 g) at 4 levels. The organophosphorus insecticides were extracted with dichloromethane and cleaned up with a mixture of Celite 545–activated carbon (4 + 1). The extracts were analyzed by gas chromatography using a nitrogen-phosphorus detector. Analysis of fortified Job's-tears shows average recoveries ranged from 73.90–98.70%, 86.31–93.15%, 84.92–96.22%, and 83.29–104.23% at 0.05, 0.1, 0.5, and 1.0 mg/kg levels, respectively. The minimum detectable amount ranged from 1.0 × 10−10 to 5.0 × 10−10 g, and the limit of quantitation for the method was 0.05 mg/kg. The method is rapid, simple, sensitive, reproducible, and applicable to the determination of these 11 organophosphorus insecticides in Job's-tears.

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