scholarly journals COMPATIBILITY OF BORROW MATERIAL FOR BEACH FILLS

1974 ◽  
Vol 1 (14) ◽  
pp. 77
Author(s):  
R.G. Dean
Keyword(s):  
Standard Deviation ◽  
Size Distributions ◽  
Simple Method ◽  
Mean Diameter ◽  
Single Graph

A simple method is presented for estimating the relative compatibility of borrow material being considered for beach fill purposes. The method defines the "compatible" fraction of the material as that coarser portion with the same mean diameter (in "phi" measure) as the native material on the beach. A single graph is presented which allows determination of the number of units of borrow material required to obtain one unit of compatible material. Use of this method requires that the size distributions be reasonably represented by the "lognormal" relationship and also requires knowledge of the means of the native and borrow materials and the standard deviation of the borrow material (all in phi measure). This method overcomes shortcomings of the Krumbein-James method published in 1965. Several examples are presented illustrating the application of the method presented in this paper.

Determination of diltiazem based on the reduction of Cu(II)–BCA complexes in micellar medium

2010 ◽  
Vol 88 (6) ◽  
pp. 533-539 ◽  
Author(s):  
Larissa Zuppardo Lacerda Sabino ◽  
Daniele Cestari Marino ◽  
Horacio Dorigan Moya
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Confidence Level ◽  
Limit Of Detection ◽  
Calibration Graph ◽  
Micellar Medium ◽  
Solution Ph ◽  
Simple Method ◽  
Relative Standard

A simple method was developed for determining microquantities of diltiazem, based on the reduction of copper(II) in buffered solution (pH 7.0) and the use of a micellar medium containing 4,4′-dicarboxy-2,2′-biquinoline acid. The copper(I) produced reacts with 4,4′-dicarboxy-2,2′-biquinoline acid and the complexes formed are spectrophotometrically measured at 558 nm. A typical calibration graph shows good linearity (r = 0.993) from 20 to 100 μg mL–1 of diltiazem. The limit of detection and relative standard deviation were calculated as 12 μg mL–1 (99% confidence level) and 3.5% (40 μg mL–1; n = 6), respectively, with a mean recovery value of 96.5% found in pharmaceutical dosages. A straightforward and effective way to recycle the reagents is addressed. The hazardous aspects of the Cu(I)–BCA reaction are presented as well.

scholarly journals A simple method for determination of deoxynivalenol in cereals and flours

2011 ◽  
Vol 20 (No. 2) ◽  
pp. 63-68 ◽  
Author(s):  
F. Kotal ◽  
Z. Radová
Keyword(s):  
Regression Analysis ◽  
Standard Deviation ◽  
Limit Of Detection ◽  
Linear Regression Analysis ◽  
Fast Method ◽  
Immunoaffinity Column ◽  
Simple Method ◽  
Relative Standard ◽  
Certified Value

An effective and fast method for determination of deoxynivalenol (DON) in cereals and flours has been developed. The immunoaffinity column was used for the isolation of DON from wheat, corn, rice and flour extract. The determination was carried out by using the HPLC/UV method. The limit of detection was 0.02 mg/kg. The recoveries for the assay range 0.1 to 2 mg/kg were generally higher than 80%, ranging from 83 to 96% with an average relative standard deviation of 3.8%. The trueness of the method using the DON test – HPLC column was established by use of certified reference material CRM 379. The certified value was 0.67 mg/kg. The result obtained from three replicates was 0.68 ± 0.05 mg/kg. The corresponding confidence interval at 95% probability ranged from 0.63 to 0.73 mg/kg. A comparative study of the DON testTM – HPLC/UV and the Mycosep 225 – GC/ECD methods was carried out. Six naturally contaminated wheat samples were analysed by both methods. Linear regression analysis demonstrates that DON testTM – HPLC is a statistically significant predictor of the GC/ECD method using the Romer Mycosep 225 column.  

scholarly journals Simultaneous Determination of N-Butylscopolamine and Oxazepam in Pharmaceutical Formulations by First-Order Digital Derivative Spectrophotometry

2005 ◽  
Vol 88 (4) ◽  
pp. 1173-1178 ◽  
Author(s):  
Maria Inés Toral ◽  
Marcelo A Muñoz ◽  
Sandra L Orellana
Keyword(s):  
Standard Deviation ◽  
Simultaneous Determination ◽  
Relative Standard Deviation ◽  
Pharmaceutical Formulations ◽  
Derivative Spectrophotometry ◽  
Simple Method ◽  
Zero Crossing ◽  
First Order ◽  
Relative Standard

Abstract A simple method has been developed for the simultaneous determination of N-butylscopolamine bromide and oxazepam in pharmaceutical formulations using first-order digital derivative spectrophotometry. Acetonitrile was selected as the solvent in which both compounds showed well-defined bands. Both analytes showed good stability in this solvent when solutions of the analytes were exposed to light and temperatures between 20° and 80°C. The simultaneous determination of both drugs was performed by the zero-crossing method at 226.0 and 257.0 nm for N-butylscopolamine and oxazepam, respectively. The linear range of determination was found to be 2.5 × 10−7 to 8.0 × 10−5 mol/L for N-butylscopolamine and 7.1 × 10−8 to 8.0 × 10−5 mol/L for oxazepam. A very good level of repeatability (relative standard deviation) of 0.2% was observed for N-butylscopolamine and oxazepam. The ingredients commonly found in pharmaceutical formulations do not interfere. The proposed method was applied to the determination of these drugs in pharmaceutical formulations (capsules).

scholarly journals Determination of Dislodgeable Residues of N-4-Chlorobenzoyl-N’-Benzoyl-N’-tert-Butylhydrazine (RH-0345) from Grass by Liquid Chromatography

1997 ◽  
Vol 80 (2) ◽  
pp. 418-425
Author(s):  
Stephen S Skorczynskis
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Surface Area ◽  
Methylene Chloride ◽  
Threshold Value ◽  
Total Surface Area ◽  
Deionized Water ◽  
Uv Detection ◽  
Simple Method

Abstract A simple method for determining chemically and physically dislodgeable residues of N-4-chloroben-zoyl-N′-benzoyl- N′-tert-butylhydrazine (RH-0345) from grass is described. To determine chemical dis- lodgeability, a sample of fresh grass leaves is washed with deionized water containing a small amount of the wetting agent Aerosol OT-75. Quantitation of residues removed from the grass is based on the total surface area of grass analyzed. Physical dislodgeability is measured by sampling an area of turf for 1 min. Sampling is accomplished by a person wearing a dosimeter made from a common athletic sock. Grass-stained socks are extracted with 75% acetonitrile in deionized water, and the extracts are diluted with water. Quantitation of physically dislodgeable residues is based on the total RH-0345 residue adsorbed on the sock and is expressed as ng RH-0345/cm2 of sock in contact with the grass. For amounts of dislodgeable residues greater than the threshold value of 250 ng/cm2 for grass and 100 ng/cm2 for socks, extracts are analyzed directly by liquid chromatography (LC) using a C8 column and UV detection at 260 nm. For samples with significantly lower amounts of dislodgeable residues, diluted extracts are partitioned with methylene chloride. The methylene chloride containing the RH-0345 residues is evaporated just to dryness, and the residues are reconstituted in 30% acetonitrile in water and then analyzed by LC. The validated sensitivity of the method is 0.5 ng/cm2 for grass and 50 ng/cm2 for cotton socks. Grass was fortified at 0.5–10 000 ng/cm2. Average RH-0345 recovery from grass was 94 ± 10% standard deviation (SD). Apparent RH-0345 residues in control grass were 0.0558 ng/cm2. Socks were fortified at 50–40 000 ng/cm2. Average RH-0345 recovery from socks was 98 ± 7% SD. Apparent RH-0345 residues in control socks were 6.13 ng/cm2.

scholarly journals A differentiation method for separating a mixture of suspended particle size distributions

1999 ◽  
Vol 3 (2) ◽  
pp. 177-185 ◽  
Author(s):  
H. Q. Wang ◽  
J. P. Dupont ◽  
R. Lafite ◽  
R. Meyer
Keyword(s):  
Particle Size ◽  
Suspended Particle ◽  
Size Distributions ◽  
Statistical Parameters ◽  
Simple Method ◽  
Differentiation Method ◽  
Particle Size Data ◽  
Suspended Particle Size ◽  
Size Data

Abstract. A simple method is proposed to partition a mixture of two populations in suspended particle size data. The method, termed here "the differentiation method" is based on the function of the lognormal distribution. Suspended material in marine or estuarine situations often consists of difficult-to-interpret complex populations. The treatment of particle size data by the method described enables the confirmation of the lognormal law and also the demonstration of the occurrence of a combination of a number of populations which may not be distinguished by the classical Gaussian transformation or automatic methods. A simple combination of graphical and numerical techniques permits the decomposition and the easy determination of the various statistical parameters (median diameter, mean diameter, etc...). The method is applied to interpret observed size distributions of suspended particulate matter in the Seine estuary. The method enables the determination of the relative sizes of the constituent sub-populations that comprise the total suspended matter. In the example used to illustrate the method, particles are shown to be resuspended as a function of different hydrodynamic parameter.

scholarly journals Determination of Vitamin B12 in Food Products by Liquid Chromatography/UV Detection with Immunoaffinity Extraction: Single-Laboratory Validation

2008 ◽  
Vol 91 (4) ◽  
pp. 786-793 ◽  
Author(s):  
Esther Campos-Gimnez ◽  
Patric Fontannaz ◽  
Marie-Jose Trisconi ◽  
Tamara Kilinc ◽  
Catherine Gimenez ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Vitamin B12 ◽  
Large Range ◽  
Uv Detection ◽  
Average Standard Deviation ◽  
Simple Method ◽  
Relative Standard ◽  
Single Laboratory

Abstract A fast and simple method to determine vitamin B12 in foods is presented. The method allows, in addition to the determination of added cyanocobalamin, the determination of natural vitamin B12 forms, making it also applicable to nonfortified products, especially those that are milk-based. Vitamin B12 is extracted in sodium acetate buffer in the presence of sodium cyanide (100C, 30 min). After purification and concentration with an immunoaffinity column, vitamin B12 is determined by liquid chromatography with UV detection (361 nm). The method has been validated in analyses of a large range of products: milk- and soy-based infant formulas, cereals, cocoa beverages, health care products, and polyvitamin premixes. The method showed appropriate performance characteristics: linear response over a large range of concentrations, recovery rates of 100.8 7.5 (average standard deviation), relative standard deviation of repeatability, RSDr, of 2.1, and intermediate reproducibility, RSDiR, of 4.3. Limits of detection and quantitation were 0.10 and 0.30 g/100 g, respectively, and correlation with the reference microbiological assay was good (R2= 0.9442). The proposed method is suitable for the routine determination of vitamin B12 in fortified foods, as well as in nonfortified dairy products. It can be used as a faster, more selective, and more precise alternative to the classical microbiological determination.

Colorimetric and Spectrophotometric Determination of Total and Non-phenolic Alkaloids in Ipeca and Its Formulations

1979 ◽  
Vol 62 (5) ◽  
pp. 1113-1115
Author(s):  
Mohamed R I Saleh ◽  
Sawsan El-Masry ◽  
Nagwa El-Shaer
Keyword(s):  
Standard Deviation ◽  
Small Sample ◽  
Acid Extract ◽  
Simple Method ◽  
British Pharmacopoeia ◽  
Total Alkaloids ◽  
Present Procedure ◽  
Relative Standard ◽  
Chloroform Phase

Abstract A simple method, requiring no chromatographic separation, is presented for the determination of the total and non-phenolic alkaloids in ipeca and its preparations. The complex formed between the alkaloid and methyl orange at pH 5.0 is extracted with chloroform and treated with 0.1N NaOH. The liberated dye, determined at 460 nm, is a measure of the total alkaloids. The chloroform phase remaining is treated with 0.1N H2SO4, and the acid extract is measured at 283 nm for the non-phenolic alkaloids, calculated as emetine. The proposed method was successfully applied to samples of ipeca powder, ipeca tincture, and 3 British Pharmaceutical Codex mixtures containing ipeca tincture, namely, ipecacuanha mixture, pediatric; ipecacuanha and ammonia mixture, pediatric; and belladonna and ipecacuanha mixture, pediatric. The proposed method compares favorably with the Egyptian Pharmacopoeia, British Pharmacopoeia, and USP methods and has a relative standard deviation of 1.54%. The present procedure is less time-consuming and requires about 45 and 90 min for the assay of ipeca tincture and powder, respectively. Only a small sample (0.2 mL tincture or 1.0 g powder) is required.

scholarly journals Development of a Rapid Method for the Determination of Caffeine in Coffee Grains by GC-FID-A Fully Validated Approach

2017 ◽  
Author(s):  
Ioannis Pasias ◽  
Ioannis Kyriakou ◽  
Charalampos Proestos
Keyword(s):  
Standard Deviation ◽  
Internal Standard ◽  
Health Claims ◽  
Simple Method ◽  
Iso 17025 ◽  
Real Samples ◽  
Relative Standard ◽  
Commission Regulation ◽  
Independent Parameters

A simple method for the determination of caffeine in coffee grains by GC-FID is presented in the current work. The method was fully validated according to ISO 17025 requirements and European Commission regulation. The accuracy, as provided by recovery experiments was higher than 93%, and the precision, as provided by the (%)Relative standard deviation under reproducibility conditions, was lower than 5%. All independent parameters that lead in the increase of methods uncertainty were investigated. In the present work all special precautions were taken into account in order to avoid the use of an internal standard. The method was applied in real samples and possible health claims were investigated.

Development of a simple method for the determination of single nucleotide polymorphisms

2010 ◽  
Vol 34 (8) ◽  
pp. S75-S75
Author(s):  
Weifeng Zhu ◽  
Zhuoqi Liu ◽  
Daya Luo ◽  
Xinyao Wu ◽  
Fusheng Wan
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Nucleotide Polymorphisms ◽  
Simple Method ◽  
Single Nucleotide
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