Method 510 Determination of extractable magnesium potassium and sodium

Magnesium, potassium and sodium are extracted from the soil with 1 M ammonium nitrate. Ammonium nitrate, 1 M - dissolve 400 g of ammonium nitrate in water and make up to 5 l. Procedure (extraction). Transfer 10 ml (scoop filled and struck off level without tapping) of air-dry soil, sieved to 2 mm, into a bottle (e.g. wide-mouth, square HDPE), and shake on a reciprocating shaker (approximately 275 strokes of 25 mm per min) for 30 min. Filter through a Whatman No. 2 filter paper, discard the...

Method 103 Determination of total nonstarch polysaccharides

This is based on the procedure by Englyst and Cummings (1984) who performed a GLC analysis of the alditol acetate derivatives of the constituent sugars. It incorporates slight modifications as currently carried out at IGER, Aberystwyth (Paul Thomas, IGER, Aberystwyth, 2001, personal communication). The starch is first dispersed with dimethyl sulphoxide, which disrupts intermolecular hydrogen bonds, followed by hydrolysis with a-amylase and pullulanase. The former hydrolyses the straight chain...

Method 62b Determination of 2 citric acidsoluble phosphorus method for basic slags Thomas phosphate

Citric acid monohydrate, crystallized HOC.COOH(CH2COOH)2.H2O Citric acid extractant - dissolve 10 g citric acid monohydrate in water, make up to 500 ml and adjust to 20 C. This is sufficient for one sample -for a number of samples, increase quantities as appropriate. The concentration may be checked by titrating 10 ml reagent against 0.1 M NaOH using phenolphthalein indicator, when the titre should be 28.55 ml. Procedure (extraction). Weigh 5.000 g of the finely powdered basic slag sample into...

Aciddigestion of soils

There are three main reasons for digesting soils in hot acid - to determine the organic carbon content, to extract mineral elements for their total content, and to determine total nitrogen by the Kjeldahl digestion. The first is called Tinsley's wet combustion (Tinsley, 1950), and uses a highly corrosive mixture of sodium dichromate, and concentrated perchloric and sulphuric acids. For undergraduate practical classes, the safer loss on ignition method might be considered more appropriate. The...

Method 84 Extraction method for obtaining silage juice for analysis for VFAs

Extractor - the extractor is shown in Fig. 8.7, and the means of attaching the small torque wrench in Fig. 8.8. Ideally it should be constructed from stainless steel, but we only used a stainless steel threaded rod or studding (10 x 58 in, 11 t.p.i., or 254 x 15.9 mm), and the rest was machined from brass. The silage juice should not remain in contact with the brass for long, however, because the brass will be attacked by the acids. The dimensions Fig. 8.8. Attachment of torque wrench to...

Method 56ai Reduction of nitrate before digestion and colorimetric autoanalysis

Sulphuric acid converts nitrate to nitric acid 2. Salicylic acid converts nitric acid to nitrosalicylic acid 3. Zinc dust converts nitrosalicylic acid to aminosalicylic acid 4. Hot sulphuric acid converts aminosalicylic acid to ammonium sulphate, which is the same form to which protein nitrogen is converted. Salicylic acid, 2-HOC6H4COOH. Sulphuric acid-selenium reagent, approx 98 m m H2SO4 - Safety note wear PPE because this is highly corrosive. Add 4 g selenium powder to 400 ml sulphuric acid...

The Analysis of Fertilizers

There are several publications detailing standard or officially recognized methods of fertilizer analysis. These include Official Methods of Analysis of AOAC International (Horwitz, 2000) Official and Standardised Methods of Analysis, published by the Royal Society of Chemistry (Watson, 1994) and Fertilisers - Methods of Analysis used in OEEC Countries (OEEC, 1952). There are also the EEC methods, which have been implemented in the UK by the Fertilisers (Sampling and Analysis) Regulations 1996...

Method 61b with final determination by autoanalysis

The acid digest from Method 6.1b consists of a solution of 0.05 g sample in 50 ml of 50 v v H2SO4. There are therefore 50,000 pg sample in 50 ml, or 1000 pg ml-1. If the fertilizer is a super triplephosphate with approximately 20 P, this would give a solution of approximately 200 pg P ml-1. The autoanalysis method is the one described in Chapter 7 for total phosphorus in plant materials, which requires an optimum sample concentration of from 20 to 100 pg P ml-1, therefore 5 ml of the super...

Oils fats and waxes

All substances in feedstuffs logically belong to one of the six components or groups of a 'proximate analysis'. This concept goes back nearly 150 years to the first state agricultural research stations in Germany, and is also known as the Weende methods (Henneberg, 1864). They give crude, but useful, measurements of the components of feedstuffs, and adaptations of the original methods are used today. The components are as follows water (from dry matter determination) protein (from nitrogen...

Method 72 Determination of crude fibre

The EC official method is described in the Official Journal of the European Communities (EC, 1992), and uses specialized glassware. We will base the method on that of MAFF ADAS (1986, pp. 90-92), (with Crown Copyright permission), but replace the alcohol and diethyl ether (used for washing the residue) with acetone, which is safer and also used in the EC method. The AOAC method is described by Padmore (1990, pp. 80-82). The traditional method uses 0.313 M NaOH, free from carbonate, but the EC...

The Analysis of Composts

The term compost has been defined by Zucconi and Bertoldi (1987) as 'the stabilized and sanitized product of composting which is beneficial to plant growth. It has undergone an initial, rapid stage of decomposition and is in the process of humification.' The initial thermophilic stage of decomposition is the means of self-sanitizing and removing pathogens. If the compost is insufficiently humified, it is immature, and the wide C N ratio causes it to immobilize soil nitrogen as it continues to...

Aciddigestion of plant materials

The original method for the determination of nitrogen by sulphuric acid-digestion was published by Kjeldahl in 1883 and fully described by Burns (1984). Many modifications have since been made with various catalysts and acid mixtures. The digestions can be carried out in up to 40-place multiple heating units using specialized glassware which is commercially available some suppliers are listed below Digestion systems Buchi Labortechnik AG http www.buchi.com Gerhardt UK Ltd http www.gerhardt.de...

Method 512b Determination of extractable sulphur automated method

An automated method should improve reproducibility by maintaining constant conditions for the formation of the BaSO4 precipitate. A method suitable for the segmented-flow analysis of sulphate in soil and plant extracts using Skalar Analytical equipment has been proposed by Coutinho (1997). Soils are said to be extracted with double-distilled water according to the method in MAFF ADAS (1986, pp. 215-216), however, that reference uses approximately 1.5 M HCl (10 g soil extracted with 70 ml water...

Method 111 Determination of extractable organic and inorganic soil P

Acetic acid - 8-hydroxyquinoline reagent - dissolve 10 g 8-hydroxy-quinoline in a solution of 2.5 (v v) acetic acid and make up to 1 l. (The 8-hydroxyquinoline blocks the readsorption or precipitation of phosphate by active iron and aluminium during acetic acid extraction. Synonyms hydroxybenzopyridine oxine phenopyridine 8-quinolinol. Not carcinogenic, but may be harmful if swallowed, and causes irritation to eyes, respiratory tract and skin safety data sheet at http www. jtbaker.com msds...

Discussion 512 Determination of extractable sulphur

A helpful discussion of sulphur in soils and its availability to plants is found in Combs et al. (1998) and Rowell (1994, pp. 213-215). Plants absorb sulphur mainly in the form of sulphate, which is the main form of sulphur occurring in the soil solution. The SO4-S is therefore the fraction usually measured. Over 90 of the surface soil sulphur occurs in combination with organic molecules from where it is mineralized to sulphate. The SO4-S concentration has been found to increase from...

Hydrochloric Element In Plants

Chapter 1 Experimental Planning 1 Colorimeter and spectrophotometer 6 Chapter 2 Sample Preparation 17 Pre-treatment of Samples and Sample Contamination 17 Milling, Grinding and Homogenization 22 Corrections of weighings in vacuo 26 Incorrect calibration of the balance 26 Absorption of moisture by the sample 27 Absorption of moisture by the sample container 27 Chapter 4 Acid-digestion, Ashing and Extraction Procedures 30 Acid-digestion of plant materials 32 Extraction Procedures - Plant-based...

Method 54 Determination of fulvic and humic acids

Microorganisms break down plant and animal residues in the soil to form a stable dark brown organic material called humus. It is composed of a mixture of large complex molecules (molar masses 20,000-100,000 g mol-1). Lignin-type precursors result in benzene ring (aromatic) compounds substituted with hydroxyl ( OH), methoxyl ( OCH3) and carboxyl ( COOH) groups such as gallic and vanillic acids. These react by oxidation and or polymerization to form dark brown substances (Flaig, 1997) typical of...

PH determination

The pH is determined in both water and 0.1 M KCl (10 g soil + 25 ml solution) as detailed in VDLUFA (1991, section A.5.1.1). Note VDLUFA Verband Deutscher Landwirtschaftlicher Untersuchungs- und Forschungsanstalten, whose website home page is http www.vdlufa.de vdl_idx.htm with method books listed at http www.vdlufa.de vdl_2_2m.htm From the home page go to LINK-Seite for addresses of useful agricultural organizations. Balzer says that from the relationship of the two pH values, additional...

In vitro digestibility

The estimation of animal digestibility of a feedstuff is usually achieved in one of three ways in vivo, in sacco or in vitro. The first uses real animals in feeding trials and gives the most realistic results to which the other methods are correlated the second method allows feed samples contained in small permeable plastic (e.g. nylon) bags to be inserted through a cannula into the rumen or another section of the digestive tract. The last method allows the digestion of feed samples to occur in...

Method 515 Determination of heavy metals in compost

To avoid the risk of explosion from using perchloric acid, the following method uses a mixture of nitric and hydrochloric acids (aqua regia). This extractant has been satisfactorily used by ADAS for over 10 years. Overnight soaking in cold aqua regia reduces frothing on heating. The digestion period has been extended to 3 h, which also makes it suitable for plant material if there is excess organic matter in the sample, slightly more aqua regia is added at the start (Bob Llewelyn, ADAS...

Method 59c Determination of resin extractable phosphorus automated method

The extraction method of Hislop and Cooke (1968), has been outlined in Chapter 4, 'Phosphate extractants'. A blank determination without soil should be carried out. The autoanalysis manifold is shown in Fig. 5.4. Some adjustments to dilution and or readout sensitivity may be necessary to handle both Table 5.1. Shoulder colour code for peristaltic pump tubing. Purple black Purple orange Purple white 0.03 0.05 0.10 0.16 0.23 0.32 0.42 0.60 0.80 1.00 1.20 1.40 1.60 2.00 2.50 2.90 3.40 3.90...

Near Infrared Spectroscopy

Practical instructions regarding this method of analysis are beyond the scope of this book, however, some details will be given to provide a background for those wishing to make use of commercial services. Some material was originally published in Faithfull (1996). What exactly is NIRS The near infrared region of the electromagnetic spectrum is a region having a range of wavelengths slightly longer than visible light but not as long as microwaves or the longer radiowaves. A beam of light from a...

Method 59b Determination of extractable phosphorus automated method

An automated method for the Lachat QuikChem Automatic Flow Injection Ion Analyzer is given in Missouri Agricultural Experiment Station (1998), pp. 27-29, and is available free of charge from Lachat (Lachat Instruments, 1988). Sun et al. (1981) describe a method for the Tecator FIAstar flow injection system. A method for a segmented continuous flow procedure for both phosphate and potassium was devised by Armitage (1965). The parameters for the phosphate analysis using a dilute HCl soil...

Commercial Analytical Services

It is difficult to determine the validity of the wide range of methods and interpretations, claimed to be based on the Albrecht system, that are provided by commercial laboratories while they remain unpublished. Albrecht worked with US soils and a limited range of crops, and agronomic advice can only be effective if backed up by field trials under conditions prevailing in one's own country. Loveland admits that one area where the BCSR method is undoubtedly right is in its advocacy of the use of...

Bottle top dispensers

Bottle top dispensers are invaluable for the repetitive measurement of a certain volume of reagent into sample containers for extraction. For example, they find extensive use in soil analysis for dispensing the extracting reagents for phosphate, potassium and magnesium. If the volume setting is adjustable, it is essential to check the amount delivered by weighing the water. Careful priming should ensure that there are no trapped air bubbles. Some manufacturers are Bibby Sterilin Ltd http...

Discussion 62 Determination of phosphorus in fertilizers

The analysis of phosphorus in fertilizers can be achieved in many ways, and due regard must be made both to the chemical form in which the phosphorus occurs, and its solubility, and hence relative rate of availability to the plant. Phosphorus can occur in many different molecular combinations and admixed with a variety of other substances, organic and inorganic, so that it is difficult to recommend one method in preference to any other. The type and amount of accompanying trace elements can...

Fibre lignin cellulose nitrogenfree extract and starch

Crude fibre is an attempt to measure the roughage material in a feedstuff that is indigestible as far as the animal is concerned. It is an attempt to approximate the effect on the feedstuff of the digestive processes within the digestive tract by the use of inorganic chemicals, in this case, boiling dilute sulphuric acid, then boiling dilute sodium hydroxide, and the weight loss on ignition (which corrects for mineral ash content) of the residue is the fibre content....

Dry ashing

Dry ashing is normally carried out in a muffle furnace. Large numbers of silica basins or crucibles take up a considerable amount of floor area within the furnace, therefore the larger the capacity the better. It may be advantageous to have two furnaces. Typical specifications would be interior dimensions (depth x width x height) volume Suitable furnaces are available from Stuart Scientific (Bibby) furnaces.htm muffle Carbolite Furnaces Ltd Aston Lane, Hope, Hope Valley, Sheffield S30 2RR, UK....

Discussion 63 Determination of potassium in fertilizers

If the fertilizer is a straight potassium fertilizer such as potassium chloride (muriate of potash), sulphate or nitrate, it may be extracted by shaking with water. For any fertilizer, including mixed or compound fertilizers, the AOAC official method (No. 983.02B, Preparation of sample) recommends extraction with boiling 4 ammonium oxalate solution. The ammonium oxalate was introduced to precipitate calcium, which could suppress the potassium reading by up to 2.5 in an erratic fashion (Schwer...

The Analysis of Animal Feed and Plant Materials

The official methods applying to Great Britain are found in SI 1999 No. 1663, The Feeding Stuffs Sampling and Analysis Regulations 1999. They revoke previous regulations and implement in full the various applicable European Community Directives, and the Community methods of analysis are listed in Schedule 2, part II, Annex I. EC methods in force are usually freely downloadable as HTML files from the Eur-Lex service, but repealed directives or TIFF versions of current methods from the Official...

Method 82 Determination of moisture in silage

See Chapter 4, 'Water content in silage'. The subjection of silage to oven drying causes loss of volatile components as well as water, resulting in overestimated moisture content. One way of minimizing this effect is to distil the fresh silage in the presence of toluene. Titration of the acidic distillate with 0.1 M NaOH enables a correction to be made for the volume of the volatile acids. A suitable method is given in MAFF ADAS 1986, pp. 85-87 where about 70 g silage plus 400 ml toluene is...

Method 52 Cation exchange capacity exchangeable bases and base saturation

Percentage base saturation Cation exchange capacity CEC 100 x TEB CEC7 the sum total of exchangeable cations that a soil can adsorb the CEC determined with 1 M ammonium ethanoate ammonium acetate buffered at pH 7.0 the sum of the exchangeable cations Al3 , H , Ca2 and Mg2 extracted by 1 M potassium chloride the sum of the exchangeable 'basic' cations Ca2 , Mg2 , K , Na and NH4 acted with 1 M ammonium ethanoate at pH 7.0. Discussion. The colloidal clay and humus soil fractions are negatively...

Method 51 Determination of extractable boron

The predominant form of boron in soil solution is H3BO3, but above pH 9.2, H2BO3 may predominate. Hot-water extraction is the most widely accepted procedure for determining the amount of boron that is available to plants, and correlated best with the incidence of black spot in garden beets Missouri Agricultural Experiment Station, 1998 . The final determination is best performed using an ICP spectrometer, but this may not always be available, so a colori-metric method will be described. Methods...

Method 74 Determination of neutral cellulase plus gamanase digestibility NCGD of feeding stuffs

The method is based on that of MAFF 1993b and is discussed in Chapter 4. It is intended for samples of compound feeds or feed mixtures. Filter tubes - a special sintered borosilicate glass filter tube with Suba-Seal and plastic cap is available from Soham Scientific, Unit 6, Mereside, Soham, Ely, Cambs CB7 5EE, UK, and is shown in Fig. 7.1. Enzymes - test kits of consistent quality are obtainable from Biotal Limited, 5 Chiltern Close, Cardiff, CF4 5DL, UK tel. 44 0 2920 766716, fax 44 0 2920...

Method 71a Determination of acid detergent fibre

Acid detergent solution - add 100 g cetyl trimethylammonium bromide CTAB , also called hexadecyltrimethylammonium bromide, technical grade, to 2.5 l of 1 M sulphuric acid, stir to dissolve and make up to 5 l Sulphuric acid, 1 M - add carefully 56 ml sulphuric acid approximately 98 m m H2SO4 and 18 M to about 400 ml water in an 800-ml beaker and stir to dissolve. Transfer with washings to a 1-l volumetric flask, make up to the mark and mix Octan-2-ol also called 2-octanol capryl alcohol...

Method 76 Determination of nitrate in plant material by autoanalysis

See the discussion with references in Chapter 4 'Nitrate and water soluble carbohydrate'. Soil extracts low in colour may also be analysed by this procedure by taking a 10-ml scoop of fresh or thawed soil. The official Bran Luebbe AutoAnalyzer method for nitrate and nitrite in soil, plant and fertilizer extracts is reproduced with permission in Appendix 5. Ammonium chloride buffer, pH 7.5 - dissolve 400 g ammonium chloride NH4Cl , 40 g EDTA disodium salt, 40 g sodium dihydrogen phosphate...

Discussion 84 Determination of volatile fatty acids VFAs in silage

Aminex Hpx 87h

We still await a routine method for the rapid analysis of large batches of silage samples for VFAs. Although initially expensive, the use of NIRS on fresh silages would be ideal, but sufficiently robust equations for components other than lactic, acetic, propionic and butyric acids are not yet widely available, although it is reported that commercial services are offering VFA analysis by NIR. The abstract of the poster by Deaville and Givens 1996 is apparently the only published data in this...

Acknowledgements

First, I would like to express my gratitude to the teachers, lecturers and industrial scientists who have instilled a high regard for practical analytical chemistry, with the need for care, accuracy, and the development of a skilful and safe technique. There are a number of individuals who have been most helpful in my search for information. It is difficult to remember everyone I have consulted over a period of 18 months, and my sincere apologies for any omissions. They include the following,...

Discussion 710 Determination of total phosphorus in plant material and feeding stuffs

The official EC method may be downloaded from This is document 371L0393 which is presented in the Official Journal No. L279, 20.12.71, p.7 , and is the Second Commission Directive 71 393 EEC of 18 November 1971. The determination of total phosphorus appears as Part III of the Annex. It is a molybdovanadate colorimetric procedure with the absorbance measured at 430 nm. The AOAC alkalimetric ammonium molybdophosphate and photometric molybdovanadate methods for animal feed are described by Padmore...

Method 73 Determination of modified acid detergent fibre MAD fibre

This modification to the ADF method was designed to improve the relationship between the ADF and digestibility in ruminants. The sample drying temperature of 95 C, however, means it is unsuitable for assaying heat damage and unavailable protein Van Soest, 1982 . The method below is based on that given in MAFF ADAS 1986, pp. 93-94 , with Crown Copyright permission. See Chapter 4 for further discussion on fibre extraction procedures. Acetone, commercial 'drum' grade Sulphuric acid-CTAB solution -...