DETERMINING AMMONIUM OXALATE-EXTRACTABLE Si IN SOILS

1986 ◽  
Vol 66 (4) ◽  
pp. 751-755 ◽  
Author(s):  
C. WANG ◽  
P. A. SCHUPPLI
Keyword(s):  
Atomic Absorption ◽  
Key Words ◽  
Podzolic Soil ◽  
Ammonium Oxalate ◽  
Podzolic Soils ◽  
Significant Difference ◽  
Key Words Oxalate

Determination of oxalate-extractable Si and Al is useful in assessing the degree of accumulation of allophane-like materials in Podzolic soils. Three procedures were tested for determining Si: manual spectrophotometry, automated spectrophotometry and atomic absorption. For concentrations of oxalate-extractable Si above 0.5 g kg−1, there was no significant difference among results by the three procedures. For lower concentrations of Si, results by atomic absorption were higher than those by the spectrophotometric procedures. Determination by Si by autoanalyzer is the preferred procedure as it is convenient, sensitive and reliable. Key words: Oxalate Si, Podzolic soil, autoanalyzer

Determination of Calcium in Leisure Foods by Incomplete Digestion-Microemulsion Sampling-High Resolution Continuum Source Flame Atomic Absorption Spectrometry

2014 ◽  
Vol 1010-1012 ◽  
pp. 417-421
Author(s):  
Chao Li ◽  
Shang Long Chen
Keyword(s):  
High Resolution ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Flame Atomic Absorption Spectrometry ◽  
Comparative Method ◽  
Absorption Spectrometry ◽  
Continuum Source ◽  
Flame Atomic Absorption ◽  
Significant Difference

The aim of this work was to evaluate the microemulsification after incomplete digestion as sample preparation procedure for determination of Ca in leisure foods by high resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Microemulsions were prepared with digestive liquor and n-butyl alcohol as an auxiliary emulsifier after incomplete digestion treatment. The appropriate fuel flow, 70 L/h, and the optimum burner height, 5 mm, were obtained by single factor experimental design. The results showed that the correlation coefficient was better than 0.999, the characteristic concentration was 0.086 mg/L, the precision (RSD) for 6 replicate measurements of Ca was 1.7% and the average of recoveries was 102.1%. F-test and t-test (95% confidence level) in between the proposed method and the comparative method, using microwave digestion-HR-CS FAAS, had no significant difference. Therefore, the proposed method was accurate and stable with a high practical value. It provided scientific basis for determination of metal elements in food.

Anaerobic Threshold Determination With Analysis of Salivary Amylase

1997 ◽  
Vol 22 (6) ◽  
pp. 553-561 ◽  
Author(s):  
Felipe Calvo ◽  
José L. Chicharro ◽  
Fernando Bandrés ◽  
Alejandro Lucía ◽  
Margarita Pérez ◽  
...  
Keyword(s):  
Heart Rate ◽  
Key Words ◽  
Anaerobic Threshold ◽  
Exercise Test ◽  
Capillary Blood ◽  
Salivary Amylase ◽  
Continuous Increase ◽  
Laboratory Exercise ◽  
Significant Difference

The purpose of this study was to determine the anaerobic threshold from analysis of amylase concentration in total saliva during a laboratory exercise test. Each of 20 healthy young men performed both a submaximal and a maximal test on a treadmill. During the submaximal test, capillary blood and total saliva samples were collected for determination of anaerobic threshold (AT) and saliva threshold (Tsa), respectively. Tsa was defined as the point at which the first continuous increase in amylase concentration occurred during exercise. The results showed no significant difference between values of AT and Tsa when both were expressed either as running velocity or as heart rate. In addition, there existed a high correlation between AT and Tsa (r = .93, p < .001). It was therefore concluded that the analysis of amylase concentration in total saliva during exercise might be used as a valid new method for determining AT. Key words: exercise, anaerobic threshold, saliva

Determination of Copper in Plasma and Serum by Use of a Microsampling Cup in Atomic Absorption Spectrometry

1974 ◽  
Vol 20 (9) ◽  
pp. 1199-1203 ◽  
Author(s):  
Arthur F Ward ◽  
Douglas G Mitchell ◽  
Murray Kahl ◽  
Kenneth M Aldous
Keyword(s):  
Blood Plasma ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Absorption Spectrometry ◽  
Precise Determination ◽  
Analytical Sensitivity ◽  
Relative Standard ◽  
Significant Difference ◽  
Determination Of Copper

Abstract A microsampling cup procedure is described for rapid, precise determination of copper in plasma. Conventional Delves-cup atomic absorption spectrometry does not yield usable copper signals with blood plasma samples. Analytical sensitivity was improved 11-fold by use of cups fitted with an axial hole, a triangular cup-holding loop, and a smaller-bore absorption tube. The modified procedure yields relative standard deviations of 4-6% at the level of 95 µg of copper per deciliter. Analysis of 100 samples of blood plasma by both the microsampling cup procedure and a solvent-extraction atomic absorption procedure showed no significant difference between the two sets of data (P &lt;.02).

scholarly journals Investigating the Influence of Biochar Amendment on the Physicochemical Properties of Podzolic Soil

Agriculture ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 471
Author(s):  
Ratnajit Saha ◽  
Lakshman Galagedara ◽  
Raymond Thomas ◽  
Muhammad Nadeem ◽  
Kelly Hawboldt
Keyword(s):  
Physicochemical Properties ◽  
Podzolic Soil ◽  
Water Drop ◽  
Morphological Structure ◽  
Field Capacity ◽  
Total Carbon ◽  
Soil Water Retention ◽  
Podzolic Soils ◽  
Significant Difference ◽  
Biochar Amendment

Research into biochar, as an amendment to soil, has increased over the last decade. However, there is still much to understand regarding the effects of biochar type and rates on the physicochemical properties of different soil types. This study aimed to investigate the effects of biochar application on the physicochemical properties of podzolic soils. Soil samples were collected from the research site in Pasadena, Newfoundland, Canada. Experimental treatments consisted of three types of soils (topsoil, E-horizon soil and mixed soil (topsoil 2: E-horizon soil 1)), two biochar types (granular and powder) and four biochar application rates (0%, 0.5%, 1% and 2% on a weight basis). Ten physicochemical parameters (bulk density (BD), porosity, field capacity (FC), plant available water (PAW), water repellency (WR), electrical conductivity (EC), pH, cation exchange capacity (CEC), total carbon (TC), and nitrogen (N)) were investigated through a total of 72 experimental units. Biochar morphological structure and pore size distribution were examined using a scanning electron microscope, whereas specific surface area was assessed by the Brunauer−Emmett−Teller method. The result indicated that the E-horizon soil was highly acidic compared to control (topsoil) and mixed soils. A significant difference was observed between the control and 2% biochar amendment in all three soil mixtures tested in this experiment. Biochar amendments significantly reduced the soil BD (E-horizon: 1.40–1.25 > mixed soil: 1.34–1.21 > topsoil: 1.31–1.18 g cm−3), increased the CEC (mixed soil: 2.83–3.61 > topsoil: 2.61–2.70 > E-horizon: 1.40–1.25 cmol kg−1) and total C (topsoil: 2.40–2.41 > mixed soil: 1.74–1.75 > E-horizon: 0.43–0.44%). Water drop penetration tests showed increased WR with increasing biochar doses from 0 to 2% (topsoil: 2.33–4.00 > mixed soil: 2.33–3.33 > E-horizon: 4.00–4.67 s), and all the biochar–soil combinations were classified as slightly-repellent. We found significant effects of biochar application on soil water retention. Porosity increased by 2.8%, FC by 10%, and PAW by 12.9% when the soil was treated with powdered biochar. Additionally, we examined the temporal effect of biochar (0 to 2% doses) on pH and EC and observed an increase in pH (4.3–5.5) and EC (0.0–0.20 dS/m) every day from day 1–day 7. Collectively the study findings suggest 2% powder biochar application rate is the best combination to improve the physicochemical properties of the tested mixed podzolic soil. Granular and powdered biochar was found to be hydrophobic and hydrophilic, respectively. These findings could be helpful to better understand the use of biochar for improving the physicochemical properties of podzolic soils when used for agricultural practices in boreal ecosystems.

Determination of Manganese in Leisure Foods by Incomplete Digestion-Microemulsion Sampling-High Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry

2014 ◽  
Vol 1033-1034 ◽  
pp. 643-647
Author(s):  
Jing Zhi Miao ◽  
Shang Long Chen ◽  
Chao Li ◽  
Yong Hua Wu
Keyword(s):  
High Resolution ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Graphite Furnace ◽  
Absorption Spectrometry ◽  
Chemical Modifier ◽  
Continuum Source ◽  
Significant Difference ◽  
Graphite Furnace Atomic Absorption

A fast and effective method was developed for determination of Mn in leisure foods by incomplete digestion-microemulsion sampling-high resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS). Microemulsions were prepared with digestive liquor and n-butyl alcohol as an auxiliary emulsifier after incomplete digestion treatment. The factors influencing determination were investigated by single factor experimental design. The optimal determination conditions were found as follows: the tartaric acid (1 mg/mL) was added as a chemical modifier with the volume of 4 μL; pyrolysis temperature 1100°C; atomization temperature 2000°C. The results showed that the correlation coefficient was better than 0.996, the characteristic concentration was 0.09 μg/L, the precision (RSD) for 6 replicate measurements of Mn was 2.8% and the average of recoveries was 97.3%. F-test and t-test (95% confidence level) in between the proposed method and the microwave digestion-HR-CS GFAAS method had no significant difference. Therefore, the proposed method was accurate and stable with a high practical value. It provided scientific basis for determination of metal elements in food.

scholarly journals Synthesis of 6-(2-Methoxynaphthyl)-2,3-dihydro-1,2,4-triazine-3-thione as a New Reagent for Spectrophotometric Determination of Copper

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Maliheh Barazandeh Tehrani ◽  
Hutan Ghanbari ◽  
Effat Souri ◽  
Fazel Shamsa ◽  
Mohsen Amini
Keyword(s):  
Atomic Absorption ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Dental Alloy ◽  
Absorption Method ◽  
Limit Of Quantification ◽  
Amyl Nitrite ◽  
Significant Difference ◽  
Determination Of Copper

A simple, sensitive, accurate, and green spectrophotometric method for the determination of Cu(II) using newly synthesized reagent, 6-(2-methoxynaphthyl)-2,3-dihydro-1,2,4-triazine-3-thione (MNDTT), has been developed. MNDTT was synthesized based on the acylation of methoxy naphthalene and reaction of the product with amyl nitrite, which upon reaction with thiosemicarbazide yielded 6-(2-meyhoxynaphthyl)-2,3-dihydro-1,2,4-triazine-3-thione. MNDTT produces a dark red complex with copper in methanol according to the 1 : 2 stoichiometry. Beer’s law was obeyed over the concentration range of 2.5–20 µg/mL withr2=0.992. The limit of detection and limit of quantification were 0.33 and 1.10 µg/mL, respectively. Within-day and between-day precision values were less than 3.68%. Finally, the method has been applied to a dental alloy (110-plus) successfully and the results were compared with atomic absorption method. The results showed that there was no significant difference between the two methods (P>0.05).

scholarly journals Values of surveyed adolescents during the covid-19 pandemic. Analysis and report

2021 ◽  
Vol 10 ◽  
pp. 84-93
Author(s):  
Mateusz SZAST ◽  
Keyword(s):  
Young People ◽  
General Population ◽  
Key Words ◽  
Life Strategies ◽  
Representative Survey ◽  
Value System ◽  
External Appearance ◽  
A Value ◽  
Significant Difference

The aim of this article is to highlight research among young people living in and around Krakow regarding their axiology. The research was analyzed taking into account publicly available COBS representative survey data, as well as research by another author who carried out a similar project in 2016 in Wroclaw. Taking into account the nationwide (representative) research regarding axiology in the plague period, this article notes some discrepancies in terms of values, as the respondents value faith the least, they attach increasingly less importance to external appearance as well as money, at the same time they value tolerance, acceptance, love, friendship and only family the most. Thus, one can observe a significant difference in the understanding or determination of life strategies of the younger generation in relation to the general population of Polish women and men, for whom family and faith are of great significance. Knowledge as a value is more highly valued by respondents than family, friends giving way to health. Honesty and freedom were rated the highest. It can be concluded that for the surveyed people affiliate values are important (love, friendship, tolerance, freedom), with a slightly smaller orientation to values building the sense of stability and success in life (money, appearance), and the least orientation to autotelic values, i.e. faith. Key words: values, axiology, value system, youth.

Quality-control sera for routine determination of aluminum by electrothermal atomic absorption spectroscopy.

1983 ◽  
Vol 29 (11) ◽  
pp. 1966-1968 ◽  
Author(s):  
F Y Leung ◽  
A R Henderson
Keyword(s):  
Quality Control ◽  
Atomic Absorption ◽  
Absorption Spectroscopy ◽  
Atomic Absorption Spectroscopy ◽  
Significant Variation ◽  
Aluminum Content ◽  
Graphite Furnace ◽  
Glass Containers ◽  
Significant Difference

Abstract Several commercially available quality-control sera were analyzed for aluminum content by atomic absorption spectroscopy with a stabilized-temperature graphite furnace. The values obtained ranged between 4 and 1250 micrograms/L (0.148 to 46.235 mumol/L). No significant difference was detected for between-vial variation for four lots of quality-control sera (p greater than 0.05). Control sera stored in 1-mL polypropylene vials and frozen at -20 degrees C for up to six months showed no significant variation in aluminum content (p greater than 0.05), but those stored in their original glass containers had significantly increased aluminum content (p less than 0.001) over a four-week period.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

Sign in / Sign up

Export Citation Format

Share Document