scholarly journals Determination of total organic phosphorus in samples of mineral soils

1962 ◽  
Vol 34 (1) ◽  
pp. 187-196
Author(s):  
Armi Kaila
Keyword(s):  
Extraction Method ◽  
Organic Phosphorus ◽  
Simple Procedure ◽  
Extraction Procedure ◽  
Phosphorus Compounds ◽  
Absolute Difference ◽  
Partial Hydrolysis ◽  
Organic P ◽  
Mineral Soils

In this paper some observations on the estimation of organic phosphorus in mineral soils are reported. The fact is emphasized that the accuracy of all the methods available is relatively poor. Usually, there are no reasons to pay attention to differences less than about 20 ppm. of organic P. Analyses performed on 345 samples of Finnish mineral soils by the extraction method of MEHTA et. al. (10) and by a simple procedure adopted by the author (successive extractions with 4 N H2SO4 and 0.5 N NaOH at room temperature in the ratio of 1 to 100) gave, on the average, equal results. It seemed to be likely that the MEHTA method removed the organic phosphorus more completely than did the less vigorous method, but in the former the partial hydrolysis of organic phosphorus compounds tends to be higher than in the latter. An attempt was made to find out whether the differences between the respective values for organic phosphorus obtained by an ignition method and the simple extraction method could be connected with any characteristics of the soil. No correlation or only a low correlation coefficient could be calculated between the difference in the results of these two methods and e. g. the pH-value, the content of clay, organic carbon, aluminium and iron soluble in Tamm’s acid oxalate, the indicator of the phosphate sorption capacity, or the »Fe-bound» inorganic phosphorus, respectively. The absolute difference tended to increase with an increase in the content of organic phosphorus. For the 250 samples of surface soils analyzed, the ignition method gave values which were, on the average, about 50 ppm. higher than the results obtained by the extraction procedure. The corresponding difference for the 120 samples from deeper layers was about 20 ppm of organic P. The author recommends, for the present, the determination of the total soil organic phosphorus as an average of the results obtained by the ignition method and the extraction method.

Gas-Liquid Chromatographic Determination of Dioxathion and Quintiofos in Organophosphorus Dip Washes

1980 ◽  
Vol 63 (1) ◽  
pp. 33-36
Author(s):  
Molly I Keating
Keyword(s):  
Solvent Extraction ◽  
Extraction Procedure ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Phosphorus Compounds ◽  
Ionization Detector ◽  
Liquid Chromatographic Determination ◽  
Gasliquid Chromatography ◽  
Liquid Chromatographic

Abstract A rapid method for the analysis of dip washes is described which eliminates the usual solvent extraction procedure. The dip wash is initially diluted with acetone and then with petroleum ether. The diluted dip wash is analyzed by gasliquid chromatography, using an alkali ionization detector sensitive to phosphorus compounds. The method was applied to the determination of dioxathion (2,3-ρ-dioxanedithiol S,S-bis(O,O-diethyl phosphorodithioate)), and quintiofos (O-ethyl O-8-quinolyl phenylphosphonothioate) dip washes. Average recoveries from fouled dip washes were 100 and 104%. GLC of these compounds with an internal standard is described, which improves the precision of the method to ±2%.

scholarly journals Response Surface Optimization of a Rapid Ultrasound-Assisted Extraction Method for Simultaneous Determination of Tetracycline Antibiotics in Manure

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Lanqing Li ◽  
Mingxing Sun ◽  
Hui Zhou ◽  
Yun Zhou ◽  
Ping Chen ◽  
...  
Keyword(s):  
Response Surface ◽  
Extraction Method ◽  
Extraction Procedure ◽  
Extraction Time ◽  
Extraction Temperature ◽  
Ultrasound Assisted Extraction ◽  
Solution Ph ◽  
Assisted Extraction ◽  
Ultrasound Assisted

A rapid and cleanup-free ultrasound-assisted extraction method is proposed for the simultaneous extraction of oxytetracycline, tetracycline, chlortetracycline, and doxycycline in manure. The analytes were determined using high-performance liquid chromatography with ultraviolet detector. The influence of several variables on the efficiency of the extraction procedure was investigated by single-factor experiments. The temperature, pH, and amount of extraction solution were selected for optimization experiment using response surface methodology. The calibration curves showed good linearity (R2>0.99) for all analytes in the range of 0.1–20 μg/mL. The four antibiotics were successfully extracted from manure with recoveries ranging from 81.89 to 92.42% and good reproducibility (RSD, <4.06%) under optimal conditions, which include 50 mL of McIlvaine buffer extraction solution (pH 7.15) mixed with 1 g of manure sample, extraction temperature of 40°C, extraction time of 10 min, and three extraction cycles. Method quantification limits of 1.75–2.32 mg/kg were obtained for the studied compounds. The proposed procedure demonstrated clear reductions in extraction time and elimination of cleanup steps. Finally, the applicability to tetracyclines antibiotics determination in real samples was evaluated through the successful determination of four target analytes in swine, cow manure, and mixture of animal manure with inorganic fertilizer.

Determination of cadmium in urine by graphite-furnace atomic absorption spectroscopy.

1978 ◽  
Vol 24 (4) ◽  
pp. 681-685 ◽  
Author(s):  
O Vesterberg ◽  
K Wrangskogh
Keyword(s):  
Atomic Absorption ◽  
Extraction Method ◽  
Graphite Furnace ◽  
Simple Procedure ◽  
Heating Unit ◽  
Cadmium In Urine ◽  
Electronic Feedback ◽  
Graphite Furnace Atomic Absorption ◽  
Temperature Controlled

Abstract A simple procedure for graphite-furnace atomic absorption analysis of cadmium in urine, based on the use of a temperature-controlled heating unit, is described. The temperature of the carbon rod is measured by resistance and controlled by electronic feedback. We studied the influence of various heating times and temperatures of ashing and atomization, as well as suitable diluents. Urine samples were diluted with an equal volume of 0.3 mol/liter HNO3, and 1 to 5 microliter of the mixture was analyzed, with background correction. Signals were evaluated electronically, giving values for integrated peaks as well as for peak heights. The detection limit was 1.2 nmol/liter. The method appears to be accurate and reproducible. The CV averaged 8% for concentrations in the range 20 to 100 nmol/liter. Correlations with a chelation-extraction method was 0.994.

scholarly journals Determination of organic phosphorus in samples of peat soils

1955 ◽  
Vol 27 (1) ◽  
pp. 104-115
Author(s):  
Armi Kaila ◽  
Oili Virtanen
Keyword(s):  
Sulphuric Acid ◽  
Room Temperature ◽  
Phosphorus Content ◽  
Organic Phosphorus ◽  
Peat Soil ◽  
Acid Extraction ◽  
Peat Soils ◽  
Alkali Extraction ◽  
Mineral Soils

Attention was paid in the present paper to the fact that the precision of the values obtained by different methods for the total organic phosphorus in soil cannot be very high. Even the variation caused by the treatment of the extracts and connected with the colorimetric estimation of phosphate in the solution makes it impossible to report the results more accurately than by 10—20 ppm organic P, at least if routine analyses are in question. Although the somewhat modified methods of Dean, Wrenshall and Dyer,. Pearson, and Mehta et al. yielded equal results for the organic phosphorus content of the respective mineral soils and of most of the peat soils analyzed, the treatment with cold alkali in the Wrenshall and Dyer procedure apparently failed to extract the organic phosphorus from two peat samples as quantitatively as the treatment with hot alkali in the other methods. On the basis of this observations a new modification of the method of Wrenshall and Dyer was proposed. It consists of an extraction of 1-g sample with 25 ml of 4 N sulphuric acid at room temperature for 18 hours, followed by washing with water and two successive extractions with 100 ml of 0.5 N sodium hydroxide, the first of them for 18 hours at room temperature, the second for 4 hours at 90°C. This method was found to extract from 40 peat soil samples on the average about 97 per cent of the total phosphorus dissolved by the Kjeldahl digestion and about 9 per cent more organic phosphorus than the method of Pearson. Experiments concerning the ignition and acid extraction procedures indicated that the method of Ghani was not suitable for the determination of organic phosphorus in the twelve samples analysed. The extraction with sulphuric acid showed no marked differences between the increase in the soluble phosphorus due to the ignition when the ratio of extraction was varied from 1:40 to 1:200, and the extractant from 0.2 N acid to 5 N acid. The results obtained for 40 peat samples by ignition for one hour at 600°C and extraction of the ignited and untreated samples with 0.2 N sulphuric acid in a ratio of 1:100 for half an hour were on the average 8 per cent higher than those given by the proposed acid-alkali extraction. The total organic phosphorus content of soil may probably be somewhat higher than the figure yielded by the acid-alkali extraction and slightly lower than the value obtained by the ignition method. For the present, the most reliable result seems to be found in the average of the data given by these two methods.

scholarly journals OPTIMIZATION OF ULTRASONICATION EXTRACTION FOR DETERMINATION OF 16 POLYCYCLIC AROMATIC HYDROCARBONS IN AIR PARTICLE

2018 ◽  
Vol 56 (3) ◽  
pp. 324
Author(s):  
Duong Thi Hanh ◽  
Ha Thu Trinh ◽  
Phan Quang Thang ◽  
Nguyen Trung Dung ◽  
Nguyen Tran Dien
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Recovery Rate ◽  
Extraction Method ◽  
Extraction Procedure ◽  
Solvent Mixtures ◽  
Relative Standard ◽  
Polycyclic Aromatic

The aim of this study is to develop the quick ultrasonication extraction procedure for determination of 16 typical polycyclic aromatic hydrocarbons (PAHs) in air particles. The  determination and quantification of PAHs in air particles samples were performed using gas chromatography coupled to mass spectrometry (GC-MS) with the aid of deuterated PAH internal standards. 1ug mixture of PAHs was spiked to a quarter of quartz fiber filter and extracted with four different solvents/solvent mixtures (methanol:dichloromethane, acetone:dichloromethane; acetone:hexane; dichloromethane). Ultrasonication extraction was carried out in dark at uncontrolled and controlled ultrasonication temperature (25-28oC). The unique extraction time (20 minutes) was applied for all experiments. The results showed that high recovery rate of PAHs (82-108%) were obtained with dichloromethane (as extraction solvent) in dark at ultrasonication temperature of 25 to 28oC, while generally low recovery rate of PAHs, especially naphthalene (57%) were obtained with methanol:dichloromethane (1:1). The ultrasonication extraction method with dichloromethane showed good reproductively and repeatability with relative standard deviation of 16 PAHs below 6,14%, confirming that samples analyses were precise.  Analytical results of PAHs in air particles collected in Hanoi using the developed ultrasonication extraction procedure showed that 15 out of 16 PAHs were detected, in which high molecular weight (MW) PAHs (>5 rings) were abundance compared to low molecular weight PAHs (< 3 rings). This developed ultrasonication extraction method is quick, easy and sufficient for determination of PAHs in air particle

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