Ammonium acetate extraction

In chernozems formed on serpentinite diluvium, Co content is in the range of 10-30 mg/kg, while in chestnut and chestnut vertic soils, Co concentrations vary from 3-15 and 15-45 mg/kg, respectively. Soils on basalt, andesite and gabbro contain 15-68 mg/kg total Cu. Total Mn in chernozems is in the range of 520-850 mg/kg. Chestnut soils have 42-106 mg/kg Zn content. Total Zn in saline alkali soils is in the range of 40-60 mg/kg Zn. Bioavailable Zn (ammonium acetate-extractable Zn) in chernozems, chestnut soils and saline alkali soils of the steppe zones varies from trace amounts to 3.8 mg/kg (1-8.3% of total Zn). In chernozems of Northern Bulgaria, total B is in the range of 25-53 mg/kg. Boron increases in saline soils and saline alkali soils. 

Simard RR. Ammonium acetate extractable elements. In Carter MR (ed.), Soil Sampling and Methods of Analysis. Boca Raton, FL CRC Press 1993, pp. 39-42. 

Atomic emission spectrometry is not sufficiently sensitive to determining molybdenum at the levels at which it occurs in soils. Due to its greater intrinsic sensitivity, inductively coupled plasma atomic emission spectrometry is capable of achieving the required sensitivity. Manzoori [168] has utilised inductively coupled plasma optical emission spectrometry to determine down to 0.01 mg/1 molybdenum in 1 M ammonium acetate extracts of soils. 

Del Castilho and Rix [265] reviewed the suitability of the ammonium acetate extraction method to predict heavy metal availability in soils. 

Examples of this type of herbicide are imazapyr, m-imazamethabenz, p-imazamethabenz, m,p-imazamethabenzmethyl, imazethapyr and imazaquin. Imazapyr has been determined at the xg/kg level in 0.1 M ammonium acetate extracts of soil by microwave-assisted extraction using electron capture negative chemical ionisation mass spectrometry [432]. High-performance liquid chromatography with UV detection at 250 nm has been used to determine imazapyr in methanol extracts of soil [433]. 

Castilho, P. Del and Rix, I. (1993) Ammonium acetate extraction for soil heavy metal speciation, model aided soil test interpretation. Int.f. Environ. Anal. Chem., 51, 59-61. 

After the 1 -M ammonium acetate extraction in problem 17, the sample was rinsed twice with distilled water and the NHJ concentration of the second rinse was determined to be 180 mg L 1. The rinsed moist sample (60% moisture by weight) was then displaced with 250 mL of 1M KC1 solution and made to a final volume of 1 L. Analysis of the final 1-L solution showed 30 mg L-1 NH. Estimate the CEC (in meq/100 g) of the soil. 

Extraction of Sedimentary Constituents. The proportion of the total concentration of Fe, Mn and Zn removed from the estuarine sediments by the different extractants varied widely among sampling stations (Table II). Hydrochloric acid, acetic acid and ammonium oxalate removed a similar proportion of total Zn from all sediments. Concentrations of Zn well above detection limits were also fo-iind in the ammonia, hydroxyl-amine and ammonium acetate extracts. The quantity of Zn removed from oxidized sediments by the latter two extractants was significantly greater than reported in previous studies in which reduced sediments were extracted ( ). 

Luoma and Jenne ( ) used less involved methodology to show some correlation between extractable nuclide concentrations and the uptake by Macoma of Zn, Cd, Co and Ag from laboratory-prepared sediments. A close correlation between ammonium acetate-solubility and Zn uptake was observed. In natiire, ammonium acetate also reflected the bioavailability of Zn to Scrobicularia in the estuaries of southwest England better than did other extractants. The correlation was not sufficiently strong to have predictive value, however, and within the narrower range of Zn concentrations in San Francisco Bay no correlation was observed. The exchangeability of Zn, implied by ammonium acetate extraction, may influence the availability of the metal, but it is not the only factor determining uptake. 

Table IV presents the RBV for the iron of three breakfast cereals not fortified with iron. The two ready-to-eat cereals were sources of highly bioavailable iron, but the instant cereal was significantly lower in bioavailability than the reference salt. We have not studied the chemical nature of iron in commercially available wheat based foods. The iron that remains in the residue of 1.2 M ammonium acetate extracted wheat bran was only 71 as bioavailable as the extracted monoferric phytate (6j, but the iron of enzymatically dephytinized wheat bran, which may be complexed with amino acids, is highly bioavailable (11).

A three step extraction procedure was designed based on acetic acid extraction (step 1), hydroxylammonium chloride extraction (step 2) and hydrogen peroxide/ammonium acetate extraction (step 3). This scheme (described elsewhere [22]) was tested in two interlaboratory trials on Cd, Cr, Cu, Ni, Pb and Zn on freshwater sediment reference materials [23,24], the results of which are summarised in Table 9.6. 

Analyze directly the ammonium acetate extract for Na and K in the flamephotometer. Standard Curve for Sodium... 

Where atomic absorption spectrophotometry is possible the ammonium acetate extract can be directly analysed for Ca and Mg. The spectrophotometric standards are prepared in the ammonium acetate solution and both the standard and extracts are read against ammonium acetate as blank. If AAS is not possible the calcium and magnesium are analysed by complexometric titrations using ethylene diamine tetra acetic acid (EDTA). 

Rowbottom, W. H. (1991). Determination of ammonium acetate extractable molybdenum in soil, and aqua regia (hydrochloric acid and nitric acid,... 

Cuprous ammonium acetate extraction. Butadiene is purified by aqueous CAA extraction in a liquid-gas countercurrent process developed by Exxon (67-69). The cuprous salt forms a soluble addition complex with butadiene, which is decomposed by heat thus the process is adaptable to countercurrent multistage equipment. Typically, the C4 hydrocarbon mixture with a butadiene content of 30-40% contacts the CAA solution in a countercurrent fashion in a series of mixer-settlers. Cooling to ca -15°C is required to promote complex formation. The more saturated hydrocarbons, butanes, and butenes are first removed by distillation. Butadiene is released from the complex by further heating to 80° C. After ammonia is removed by washing with water, distillation produces butadiene that is 98-99% pure. Acetylenes and allenes are extracted with the butadiene but must... 

To each reaction, add 115 pi of RNase-free H2O and 15 pi of 3 m ammonium acetate. Extract with phenohchloroform and precipitate the RNA with an equal volume of 2-propanol at -20 C for 1 hour. Aspirate the 2-propanol from the pellet and resuspend the RNA in 50 pi of injection buffer for annealing. 

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