Determination of chloride, bromide, nitrate, phosphate and sulfate in 20% NaOH after inline neutralization by cation exchange on the 793 IC Sample Prep Module using anion chromatography with conductivity detection after chemical suppression.

AN-S-117

Chloride, nitrate and sulfate in sodium thiocyanate

Determination of chloride, nitrate and sulfate in sodium thiocyanate using anion chromatography with conductivity detection after chemical suppression.

AN-S-104

Nitrate and sulfate in sodium phosphinate (sodium hypophosphite)

Determination of nitrate and sulfate in sodium phosphinate (sodium hypophosphite) using anion chromatography with conductivity detection after chemical suppression.

AN-S-101

Chloride and sulfate in potassium tetraborate

Determination of chloride and sulfate in potassium tetraborate (KB₄O₇ * 4 H₂O) using anion chromatography with conductivity detection after chemical suppression.

AN-S-081

Acetate, chloride, nitrate and sulfate in aluminum oxide

Determination of acetate, chloride, nitrate and sulfate in aluminum oxide using anion chromatography with conductivity detection after chemical suppression.

AN-S-077

Traces of iodide in common salt using amperometric detection

Determination of iodide in common salt using anion chromatography with amperometric detection at the silver electrode.

AN-S-060

Traces of chloride, cyanate, nitrate and sulfate in urea

Determination of traces of chloride, cyanate, nitrate and sulfate in urea using anion chromatography with conductivity detection after chemical suppression.

AN-P-014

Eight sugar components in an explosive material

Determination of rhamnose, mannose, glucose, galactose, fructose, lactose, sucrose and maltose in an explosive material using pulsed amperometric detection.

AN-O-023

Carbonate in aqueous ammonia solution

Determination of carbonate in an aqueous ammonia solution using ion exclusion chromatography with suppressed conductivity detection.

AN-N-038

Traces of iodide in acetic acid using amperometric detection

Determination of traces of iodide in acetic acid using anion chromatography with amperometric detection at the carbon paste electrode.

AN-N-001

Nitrate and perchlorate in hydrochloric acid eluate

Determination of NO₃^– and ClO₄^–in the presence of a large excess of HCl using anion chromatography with direct conductivity detection (using time program for full scale change after 18 min).

AN-M-002

Chlorite, chlorate and perchlorate in explosion residue using IC/MS coupling

Determination of chlorite, chlorate and perchlorate in explosion residue using anion chromatography with conductivity and MS detection in tandem.

AN-K-041

Water in liquid ammonia

Determination of the water content of liquid ammonia according to Karl Fischer after absorption of the water in ethylene glycol.

AN-K-019

Water in urea

The water content of urea is determined according to Karl Fischer.

AN-K-013

Water in organic peroxides

The water content of organic peroxides is determined according to Karl Fischer using two-component reagents. To prevent any unwanted side reactions the determinations are carried out at -20 °C.

AN-K-009

Water in explosive pellets

The water content of explosive pellets is determined according to Karl Fischer after extraction with methanol.

AN-K-002

Water in methyl ethyl ketone peroxide (butanone peroxide)

The water content of methyl ethyl ketone peroxide is determined according to Karl Fischer using two-component reagents in order to prevent unwanted side reactions. (Separate solvent is used to ensure a high excess of sulphur dioxide and amine in the titration vessel.)

AN-K-001

Water in potassium chlorate (KClO₃)

The water content of potassium chlorate is determined according to Karl Fischer using the oven method (300 °C).

AN-H-081

Determination of phosphoric and nitric acid in nitrophos liquors

Determination of phosphoric and nitric acids in liquors from the Nitrophos fertilizer manufacturing process.

AN-H-071

Determination of ammonium ions by titration with hypochlorite

Determination of ammonium ions in ammonium salts and mixtures containing ammonium ion.

AN-H-065

Determination of salts of carboxylic acids by aqueous acidometric titration

Determination of sodium and potassium salts of carboxylic acids in aqueous media. May be used for analysis of reagent purity.

AN-H-062

Standardization of titrant for direct titration of sodium

Standardization of titrant for direct determination of sodium.

AN-H-055

Analysis of sodium and phosphorus in sodium tripolyphosphate precursor solutions

Determination of Na and P and [Na]/[P] in precursor solutions and solids in the manufacture of sodium tripolyphosphate.

AN-H-035

Determination of phosphate in liquid fertilizer

Determination of phosphate content in liquid fertilizer.

AN-H-008

Determination of phosphate by magnesium titration

Determination of soluble orthophosphate ions, for example soluble phosphate in fertilizers such as DAP.

AN-H-003

Determination of sulfate in phosphoric acid

Determination of the sulfate content of wet process phosphoric acid.

AN-C-084

Ammonium, magnesium and calcium in liquid fertilizer

Determination of ammonium, potassium, magnesium and calcium in a liquid fertilizer using cation chromatography with direct conductivity detection..

AN-C-082

Ammonium, magnesium and calcium in fertilizer

Determination of ammonium, magnesium and calcium in a fertilizer using cation chromatography with direct
conductivity detection.

AN-C-074

Trimethylamine in hydrogen peroxide (H₂O₂)

Determination of trimethylamine in hydrogen peroxide (31 %) using cation chromatography with direct conductivity detection after inline matrix elimination, inline preconcentration and inline calibration.

AN-C-056

Sodium, ammonium, methylamine, guanidine and aminoguanidine in wastewater

Determination of sodium, ammonium, methylamine, guanidine (Gu) and aminoguanidine (Agu) in wastewater using cation chromatography with direct conductivity detection.

AN-C-045

Magnesium in ammonium sulfate

Determination of magnesium in ammonium sulfate using cation chromatography with direct conductivity detection.

AN-C-024

Ammonium and guanidinium in urea

Determination of ammonium and guanidinium in urea using cation chromatography with direct conductivity detection.

AN-C-011

Magnesium, strontium and barium in pyrotechnic mixtures

Determination of magnesium, strontium and barium in pyrotechnic mixtures using cation chromatography with direct conductometric detection.

AN-C-003

Sodium, ammonium and potassium in hydrogen peroxide (H₂O₂)

Determination of sodium, ammonium and potassium in hydrogen peroxide without decomposition or matrix elimination using cation chromatography with direct conductivity detection.

AB-240

Fully automatic determination of the phosphorus content (P₂O₅) in fertilizers

The phosphorus content of fertilizers can be determined from the phosphoric acid produced when the sample is dissolved in hydrochloric acid. Calcium ions, which would interfere with this determination, are masked by precipitation as calcium oxalate.

In the first titration the hydrochloric acid and the first hydrolysis proton of the phosphoric acid are titrated (1). Oxalate is then added to precipitate the calcium ions (2). In the second titration the second hydrolysis proton of the phosphoric acid is titrated (3).

HCl + NaOH -> H₂O (1)

H₃PO₄ -> NaH₂PO₄ + H₂O (1)

Ca²⁺ + (COO)₂^2- -> Ca(COO)₂ (2)

NaH₂PO₄ + NaOH -> NaHPO₄ + H₂O (3)

In this determination the «activate pulse», «auto start» and «cycle lines» of the Titrino are used.

AB-132

Polarographic determination of molybdenum in strongly ferruginous materials

A method is described in this Bulletin that allows molybdenum to be determined in steel and other materials containing a high iron concentration. Mo(VI) is determined at the dropping mercury electrode by catalytic polarography. The determination limit is approx. 10 μg/L Mo(VI).

AB-129

Potentiometric determination of orthophosphates, metaphosphates and polyphosphates

After acid digestion, the sample solution is neutralized with sodium hydroxide to form sodium dihydrogen phosphate. An excess of lanthanum nitrate is added and the released nitric acid is then titrated with sodium hydroxide solution.

NaH₂PO₄ + La(NO₃)₃ -> LaPO₄ + 2 HNO₃ + NaNO₃

This determination method is suitable for higher phosphate concentrations.

AB-100

Biamperometric determination of potassium and/or ammonium

The potassium (or ammonium) ion is precipitated with sodium tetraphenyl borate, and the excess of this reagent back-titrated against the thallous ion, using biamperometric endpoint detection. Ammonium can either be titrated together in an acid solution, of driven off my previous boiling in an alkaline solution. Methods are given for determining potassium in the presence of large excesses of sodium, ammonium, calcium and magnesium.

AB-071

Determining the pH value and redox potential in soil samples

The pH and redox potential of a soil provide important information about its properties. By using these values statements can be made about plant growth, bacterial activity, any fertilizers that may be required, aggressive behavior toward buildings, etc.

AB-70

Polarographic determination of nitrate in water samples, soil and plant extracts, vegetable juices, meat and sausages, fertilizers, liquid manure, etc.

The photometric determination of nitrate is limited by the fact that the respective methods (salicylic acid, brucine, 2,6-dimethyl phenol, Nessler’s reagent after reduction of nitrate to ammonium) are subject to interferences. The direct potentiometric determination using an ion-selective nitrate electrode causes problems in the presence of fairly large amounts of chloride or organic compounds with carboxyl groups. The polarographic method, on the other hand, is not only more rapid, but also practically insensitive to chemical interference, thus ensuring more accurate results. The limit of quantification depends on the matrix of the sample and is approximately 1 mg/L.

AB-053

Determination of ammonium or Kjeldahl nitrogen

The potentiometric titration of Kjeldahl nitrogen is one of the most widely employed analytical methods. Many of the standard procedures used in the food and animal feed industry, in wastewater and refuse analysis as well as in agriculture and the fertilizer industry are based on this method. Extensive test series (interlaboratory tests) have been carried out to determine and optimize the recovery rates and digestion conditions. The knowledge derived from these tests has been integrated in the corresponding standards.

Normally, the samples are digested with concentrated sulfuric acid together with a catalyst. The ammonium sulfate formed is distilled off as ammonia in alkaline solution, collected in an absorption solution and then titrated.

The first part of this Bulletin describes in detail the potentiometric determination of nitrogen after distillation of the digestion solution. The second part indicates the possibilities of coulometric titration (without distillation).

AB-039

Potentiometric determination of nitrating acid

A potentiometric, non-aqueous method is described for analyzing nitrating acid using cyclohexylamine as titrant. Both sulfuric and nitric acid can be determined quantitatively.