Sample acid digestion

Blood and urine 206Pb addition and sample acid digestion lead coprecipitation by addition of Ba(N03)2, IDMS No data 98-99 Manton and Cook 1984... 

Oxidative decomposition by wet ashing is the most widely used sample preparation method for milk samples. Acid digestion involves the use of mineral acids and oxidizing agents to dissolve the sample. Some of the acids commonly used in these procedures are HC1, HNO3, H2S04, and HCIO4. Wet decomposition can be performed with either open or closed systems. Open systems entail... 

Grind air-dried or fresh samples acid digest with HN03 and HCI add EDTA neutralize with NH4OH add HCI shake with decalin centrifuge decalin layer read decalin solution with fluorometer at 525 nm within 5 minutes Fluorometric method <4x1 O 6 g/g No data AOAC 1984 (method 3.102 to 3.107)... 

A web-site dedicated to sample preparation, which contains useft information about acid digestion and microwave digestion, is found at... 

The total phosphoms content of the sample is determined by method AOCS Ja 5-55. Analysis of phosphoUpid in lecithin concentrates (AOCS Ja 7-86) is performed by fractionation with two-dimensional thin-layer chromatography (tic) followed by acid digestion and reaction with molybdate to measure total phosphorous for each fraction at 310 nm. It is a semiquantitative method for PC, PE, PI, PA, LPC, and LPE. Method AOCS Ja 7b-91 is for the direct deterrnination of single phosphoHpids PE, PA, PI, PC in lecithin by high performance Hquid chromatography (hplc). The method is appHcable to oil-containing lecithins, deoiled lecithins, lecithin fractions, but not appHcable to lyso-PC and lyso-PE. 

The most universal method for sample destmction before SPh metal determination (Ee, Mo, A1 and etc.) is the sulfur acid digestion at high temperature by Kjeldall. It can be enforced by microwave decomposition in the microwave oven. 

Known concentrations of Sn solutions were spiked Into acid digested samples of Ps. 244 which had been exposed to 10 ppm solutions of Bu Sn (x = 0,1,2,3). Atomic absorption analysis of these samples allowed for the calculation of the amount of tin accumulated on the cell by the method of multiple additions Q6). 

Determined by inductively coupled plasma-mass spectrometry of acid digested catalyst samples Calculated from X-ray diffraction peak broadening at (101) foranatase and (110) formtile TiOa Mean particle diameter measured from transmission electron microscopy pictures of gold catalysts... 

Principles and Characteristics Instead of thermal initiation, microwave decomposition may be of use for sample preparation involving combustion or acid digestion. The advantages over thermal initiation lie in the shorter time needed (minutes instead of hours). Microwave oven digestion (MOD) systems are not analytical instruments. Functionally, they are chemical... 

Matusiewicz [63,68] has reported the development of a high-pressure, high-temperature, focused-microwave-heated acid (HNO3) digestion system. This microwave technique requires only about 3 % of the time necessary for the thermal high-pressure (HPA) technique. The technique of microwave heating samples in sealed containers to speed up acid digestion has been in widespread use for the past few years [69,70]. 

TXRF is most applicable to liquid samples, but success has also been achieved with direct analysis of some solids, e.g. very thin sections of organic tissue and polymer film. Alternatively, small amounts of solid material can be analysed by TXRF after acid digestion. 

The Cr203 content of each catalyst was determined by atomic absorption spectroscopy (Varian/Spectr AA-20 plus) on acid-digested samples. Total surface areas were determined by a single point BET method (nitrogen adsorption-desorption at 77.5 K) using a mixture of 29.7% N2 in helium. Samples were wet-loaded into the flow tube and dried at 423 K in a hydrogen flow for 15 minutes and then for another 30 minutes at 513 K before cooling in helium. 

Testes, liver, spleen, kidney Dicing of sample and digestion in hot acid in a Paar bomb evaporation redissolution in HCI/HNO3 ICP/AES 10-50 pg/L >80 Que Hee and Boyle 1988... 

Soil, wastes, and groundwater Acid digestion of sample, dilution with water, and filtration AAS (EPA method 7420) GFAAS (EPA method 7421) 0.1 mg/L 1 pg/L No data No data EPA 1986e... 

A 68 element ICP-MS scan was performed on one dried white-colored paint sample. The chemical elements scanned for during the ICP analysis and the detection limits are provided in Table 5. Approximately 0.5 g of each sample was prepared by an acid digestion technique prior to conducting the ICP-MS analysis. Shown in Table 6 are the quantified ICP-MS results for the sample. Elements scanned for but not detected are either not present in the sample or may be present below the detection limit. 

Conventional techniques such as solvent extraction followed by gas chromatography mass spectrometry (GCMS), and acid digestions followed by GCMS have all been performed on meteorite samples but all information about the location within the sample is lost during a digestion processes. However, microprobe laser desorption studies allow the profiling of material within the meteorite sample. 

A chloric acid digestion was used by Backer 2 391 for the preparation of tissue samples. The digest is simply diluted to determine iron, zinc, and copper. The tantalum sampling boat technique was used by Emmermann and Luecke 2531 to measure lead, zinc, and silver in prepared soil solutions. White 1S81 treated ashed plants with hydroxylamine in IN hydrochloric acid to reduce and dissolve oxides of manganese, prior to its determination by atomic absorption spectroscopy. 

Soil samples were sieved to two size fractions <63 pm and <2 mm. Samples were analyzed for multi-element geochemistry by inductively coupled plasma/mass spectrometry (ICP/MS) following a near total 4-acid digestion. 

The REE analysis was carried out in twenty two sand samples by using 0.1 g of dried sample (mesh 200) and digested with strong acid. Digestion was performed in teflon vessels using 4 ml of HCI 04 and 10 ml HF. This mixture was heated and residue dissolved in distilled water. 

Most average homes contain a microwave oven. Researchers have taken that same technology and applied it to sample extraction. Using microwave technology with acidic solutions has become a commonplace replacement for traditional acid digests. The sample is placed in a closed, chemical-resistant vessel and heated in a microwave. This process is much faster than hot-plate techniques and has become widely accepted by such agencies as the US EPA. 

Safety While we list safety last, safety must always be at the top of the list of considerations. For example, you should not even consider a method requiring perchloric acid digestion for sample preparation unless your facility has the appropriate quality fume hood. In Table 21.10, we have listed some of the many safety issues you need to evaluate. 

---