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Total Nitrogen in Waters

SOP: 1340

Total nitrogen, organic nitrogen and Kjeldahl nitrogen.

An alkaline persulphate digestion converts all forms of nitrogen to nitrate.  The nitrate then reacts with chromotropic acid under strongly acidic conditions to form a yellow complex.  Its absorbance is measured at 420nm.

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    Soil ChemistryWater ChemistryAsbestosEnvironmental ForensicsGas, Vapours and Dust Waste
    Sulphate SpecificationsWater Supply Pipe Selection (UKWIR)Topsoil and SubsoilSoil Methods
    Water Methods
    Bulk IdentificationSoils
    Source Water Identification
    Soil MeasurementsBoundary ReadingsOdours and Nuisance
    Waste Derived Fuels

    A number of different publications and standards cite sulphate methods. BR279 (1995) has largely been superseded by analytical procedures as detailed in TRL 447 and BRE Special Digest:1 2005 3rd Edition. In addition further reference may be made to BS EN 144-1:2009 + A1:2012 for the testing of aggregates and BS 1377:2018 for soils for civil engineering purposes.
    Water Soluble Sulphate in Soils Total Sulphur in Soils Total Sulphate in Soils

    Testing to meet the requirements of UKWIR Report Ref. No. 10/WM/03/21 Guidance for the selection of water supply pipes to be used in brownfield sites.
    pH Value of Soils Electrical Conductivity of Soils Aliphatic/Aromatic Petroleum Hydrocarbons in Soils by GCxGC-FID Volatile Organic Compounds (VOCs) in Soils by Headspace GC-MS Semi-Volatile Organic Compounds (SVOCs) in Soils by GC-MS

    Testing & reporting is undertaken in accordance with BS 3882:2015 Specification for topsoil and BS 8601:2013 Specification for subsoil and requirements for use
    pH Value of Soils Electrical Conductivity of Soils Moisture and Stone Content of Soils Extractable Cations in Soils Extractable Phosphate in Soils Acid Soluble Metals in Soils

    All Soil Methods
    pH Value of Soils Electrical Conductivity of Soils Moisture and Stone Content of Soils Soil Description Water Soluble Boron in Soils Water Soluble Sulphate in Soils Total Sulphur in Soils Sulphur (Elemental) in Soils by HPLC Water Soluble Chloride in Soils Cyanides & Thiocyanate in Soils Sulphide in Soils Total Nitrogen in Soils Extractable Cations in Soils Extractable Phosphate in Soils Extractable Ammonium in Soils Total Sulphate in Soils Acid Soluble Metals in Soils Hexavalent Chromium in Soils Loss on Ignition Total Organic Carbon in Soils Total Petroleum Hydrocarbons (TPH) in Soils by GC-FID Aliphatic/Aromatic Petroleum Hydrocarbons in Soils by GCxGC-FID Speciated Polynuclear Aromatic Hydrocarbons (PAHs) in Soils by GC-FID Volatile Organic Compounds (VOCs) in Soils by Headspace GC-MS Semi-Volatile Organic Compounds (SVOCs) in Soils by GC-MS Speciated Polynuclear Aromatic Hydrocarbons (PAHs) in Soils by GC-MS Polychlorinated Biphenyls (PCB) as Aroclors in Soils by GC-MS / GC-ECD Polychlorinated Biphenyls (PCB) ICES7 Congeners in Soils by GC-MS Organophosphorus (O-P) Pesticides in Soils by GC-MS Organonitrogen (O-N) Pesticides in Soils by GC-MS Organochlorine (O-Cl) Pesticides in Soils by GC-MS Phenols in Soils by GC-MS Phenols in Soils by HPLC

    All Water Methods
    pH Value of Waters Electrical Conductivity of Waters Total Suspended Solids Total Dissolved Solids (TDS) Biochemical Oxygen Demand (ATU BOD5) Chemical Oxygen Demand (COD) Dissolved Oxygen (DO) Anions, Alkalinity & Ammonium in Waters Alkalinity of Waters Total Hardness of Waters Cyanides & Thiocyanate in Waters Sulphide in Waters Total Nitrogen in Waters Cations in Waters by ICP-MS Metals in Waters by ICP-MS Mercury low-level in Waters by Atomic Fluorescence Spectroscopy Hexavalent Chromium in Waters Total Organic Carbon in Waters Total Petroleum Hydrocarbons (TPH) in Waters by GC-FID Aliphatic/Aromatic Petroleum Hydrocarbons in Waters by GCxGC-FID Speciated Polynuclear Aromatic Hydrocarbons (PAH) in Waters by GC-FID Volatile Organic Compounds (VOCs) in Waters by Headspace GC-MS Semi-Volatile Organic Compounds (SVOCs) in Waters by GC-MS Speciated Polynuclear Aromatic Hydrocarbons (PAHs) in Waters by GC-MS Polychlorinated Biphenyls (PCB) as Aroclors in Waters by GC-MS / GC-ECD Polychlorinated Biphenyls (PCB) ICES7 Congeners in Waters by GC-MS Organophosphorus (O-P) Pesticides in Waters by GC-MS Organonitrogen (O-N) Pesticides in Waters by GC-MS Organochlorine (O-Cl) Pesticides in Waters by GC-MS Phenols in Waters by GC-MS Phenols in Waters by HPLC

    All Asbestos Methods
    Asbestos Bulk ID

    All Asbestos Methods
    Asbestos Bulk ID Water Absorption Test Identification and Quantification of Asbestos
    pH Value of Waters Electrical Conductivity of Waters Anions, Alkalinity & Ammonium in Waters Cations in Waters by ICP-MS Volatile Organic Compounds (VOCs) in Waters by Headspace GC-MS
    Volatile Organic Compounds (VOCs) in Air by Automated Thermal Desorption GC-MS
    Volatile Organic Compounds (VOCs) in Air by Automated Thermal Desorption GC-MS
    Volatile Organic Compounds (VOCs) in Air by Automated Thermal Desorption GC-MS
    Sample Preparation Ash Content Sulphur, Fluorine, Chlorine, Bromine and Iodine Fixed Carbon Oxygen by Difference Volatile Matter Biomass by Dissolution CHN Elemental Analysis Bulk Density Particle Size Distribution Moisture Content Gross Calorific Value (Higher Heating Value) & Net Calorific Value (Lower Heating Value) Determination of Trace Elements Major Elements

    Water Soluble Sulphate in Soils

    Analysis of  a water extract of sulphate prepared from an aliquot of a dried and ground soil sample by inductively

    Total Sulphur in Soils

    Total sulphur in a soil sample is determined by high temperature combustion in oxygen using an elemental analyser.  The resultant

    Total Sulphate in Soils

    Acid digestion of a sample aliquot in a heating block followed by the determination of sulphate in the extract by

    pH Value of Soils

    Measurement of the pH of a 2:1 water extract of a dried and ground soil sample using a pH meter.

    Electrical Conductivity of Soils

    Measurement of the electrical conductivity of a 2:1 water extract using a conductivity meter.

    Aliphatic/Aromatic Petroleum Hydrocarbons in Soils by GCxGC-FID

    UKAS accredited: all bands  in the range C8–C40 MCERTS accredited: all bands in the range C8–C35 aliphatic banding: >C5–C6, >C6–C8,>C8–C10,

    Volatile Organic Compounds (VOCs) in Soils by Headspace GC-MS

    UKAS & MCERTS accredited: please refer to UKAS schedule for individually accredited compounds. Analysis of an as received soil sample for

    Semi-Volatile Organic Compounds (SVOCs) in Soils by GC-MS

    UKAS & MCERTS accredited.  Base upon USEPA Method 8270 Methodology – Extraction of an as received soil sample into dichloromethane followed

    Moisture and Stone Content of Soils

    Determination of moisture and stone content of soil as percentages of its mass obtained after drying at <37°C.

    Extractable Cations in Soils

    Cations: potassium, magnesium, calcium, sodium Soil extracts are prepared by extracting dried and ground soil samples with ammonium nitrate solution.

    Extractable Phosphate in Soils

    Soil extracts are prepared by extracting dried and ground soil samples with sodium hydrogen carbonate solution. Phosphate is determined by

    Acid Soluble Metals in Soils

    UKAS & MCERTS accredited: arsenic; barium; cadmium; chromium; cobalt; copper; lead; manganese; mercury; molybdenum; nickel; selenium; zinc UKAS accredited: beryllium;

    Soil Description

    An as received soil is described in accordance with BS5930:2015 Code of practice for ground investigation.

    Water Soluble Boron in Soils

    Analysis of  a water extract of boron prepared from an aliquot of a dried and ground soil sample by inductively

    Sulphur (Elemental) in Soils by HPLC

    Aliquots of dried and ground soil are extracted into dichloromethane.  The filtered extracts are analysed by high performance liquid chromatography

    Water Soluble Chloride in Soils

    Analysis of  a water extract of chloride prepared from an aliquot of a dried and ground soil sample by discrete

    Cyanides & Thiocyanate in Soils

    Aliquots of dried and ground soil are extracted into 1M sodium hydroxide. Free cyanide: Automated acid distillation followed by colorimetric

    Sulphide in Soils

    Sulphide is released from dried and ground samples as hydrogen sulphide by steam distillation with sulphuric acid. The hydrogen sulphide

    Total Nitrogen in Soils

    High temperature combustion of the sample in oxygen using an elemental analyser.  The resultant nitrogen gas is measured by thermal

    Extractable Ammonium in Soils

    Soil extracts are prepared by extracting dried and ground soil samples with potassium chloride solution. Ammonium is determined by ‘Aquakem

    Hexavalent Chromium in Soils

    Soil extracts are prepared by extracting dried and ground soil samples into boiling water. Chromium [VI] is determined by ‘Aquakem

    Loss on Ignition

    Determination of the proportion by mass that is lost from a soil by ignition at 440°C or 550°C.

    Total Organic Carbon in Soils

    Total organic carbon (TOC) The sample is first acidified to remove any inorganic carbon.  Total organic carbon is then determined

    Total Petroleum Hydrocarbons (TPH) in Soils by GC-FID

    UKAS & MCERTS accredited: Total petroleum hydrocarbons in the range C6–C40 UKAS accredited: Gasoline Range Organics (GRO), Diesel Range Organics (DRO)

    Speciated Polynuclear Aromatic Hydrocarbons (PAHs) in Soils by GC-FID

    Acenaphthene; acenaphthylene; anthracene; benzo[a]anthracene; benzo[a]pyrene; benzo[b]fluoranthene; benzo[ghi]perylene; benzo[k]fluoranthene; chrysene; dibenz[ah]anthracene; fluoranthene; fluorene; indeno[123cd]pyrene; naphthalene; phenanthrene; pyrene Methodology – Extraction of

    Speciated Polynuclear Aromatic Hydrocarbons (PAHs) in Soils by GC-MS

    UKAS & MCERTS accredited: acenaphthene; anthracene; benzo[a]anthracene; benzo[a]pyrene; benzo[b]fluoranthene; benzo[ghi]perylene; chrysene; fluoranthene; fluorene; indeno[123cd]pyrene; naphthalene; phenanthrene; pyrene UKAS accredited: acenaphthylene;

    Polychlorinated Biphenyls (PCB) as Aroclors in Soils by GC-MS / GC-ECD

    Results are normally reported as Aroclor 1242. Methodology – Extraction of an as received soil sample into hexane/acetone (50:50) followed

    Polychlorinated Biphenyls (PCB) ICES7 Congeners in Soils by GC-MS

    ICES (International Council for the Exploration of the Sea) PCB congeners: PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, PCB180 Methodology –

    Organophosphorus (O-P) Pesticides in Soils by GC-MS

    The method includes parathion, malathion, chlorpyrifos, diazinon  plus any organophosphorus pesticides specified by the client. Methodology – Extraction of an

    Organonitrogen (O-N) Pesticides in Soils by GC-MS

    The method includes triazines plus any organonitrogen pesticides specified by the client. Methodology – Extraction of an as received soil

    Organochlorine (O-Cl) Pesticides in Soils by GC-MS

    The method includes DDT and its metabolites, the so-called ‘drins’ and Lindane, plus any determinands specified by the client. Methodology

    Phenols in Soils by GC-MS

    The method includes 24 substituted phenols, including chlorophenols. Methodology – Extraction of an as received soil sample into dichloromethane followed

    Phenols in Soils by HPLC

    The method includes resorcinol, phenol, methylphenols, dimethylphenols, 1-naphthol and trimethylphenols. Chlorophenols are not detected by this method. Methodology – Extraction of

    pH Value of Waters

    Measurement of pH using a pH meter

    Electrical Conductivity of Waters

    Measurement of the electrical conductivity using a conductivity meter.

    Total Suspended Solids

    Filtration of a mixed sample through a GF/C 1.2µm glass fibre filter and determination of the mass of residue retained

    Total Dissolved Solids (TDS)

    Calculated from conductivity utilising an electrical conductivity meter reading directly in mg/l TDS.

    Biochemical Oxygen Demand (ATU BOD5)

    Electrometric determination of dissolved oxygen in a seeded sample initially and after 5 days incubation at 20°C.

    Chemical Oxygen Demand (COD)

    Dichromate oxidation of organic matter in sample followed by colorimetric determination of residual Cr[VI].

    Dissolved Oxygen (DO)

    Electrometric determination (on site preferred), using an oxygen sensitive membrane electrode.

    Anions, Alkalinity & Ammonium in Waters

    Fluoride; chloride; nitrite; nitrate; total oxidisable nitrogen (TON); sulphate; phosphate; alkalinity; ammonium. Automated colorimetric analysis using a discrete analyser.

    Alkalinity of Waters

    Titration of the sample with a standard solution of acid using instrumental detection to end points at pH 8.3 and

    Total Hardness of Waters

    Calculated from calcium and magnesium concentrations: Total Hardness (mg/l CaCO3 equivalent) = (2.5 x Ca (mg/l)) + (4.12 x Mg

    Cyanides & Thiocyanate in Waters

    Free [or easy liberatable] cyanide, total cyanide, complex cyanide, thiocyanate. Free cyanide: Automated acid distillation followed by colorimetric development with

    Sulphide in Waters

    Sulphide is then analysed by automated colorimetric analysis on an Aquakem 600 discrete analyser using N,N–dimethyl-p-phenylenediamine.

    Total Nitrogen in Waters

    Total nitrogen, organic nitrogen and Kjeldahl nitrogen. An alkaline persulphate digestion converts all forms of nitrogen to nitrate.  The nitrate

    Cations in Waters by ICP-MS

    Sodium; potassium; calcium; magnesium. Direct determination by inductively coupled plasma – mass spectrometry (ICP-MS).

    Metals in Waters by ICP-MS

    UKAS accredited: antimony; arsenic; barium; beryllium; boron; cadmium; chromium; cobalt; copper; lead; manganese; mercury; molybdenum; nickel; selenium; tin; vanadium; zinc

    Mercury low-level in Waters by Atomic Fluorescence Spectroscopy

    Mercury is determined by atomic fluorescence spectroscopy (AFS), with a collimated UV source, wavelength 253.7 nm.

    Hexavalent Chromium in Waters

    Automated colorimetric analysis by a discrete analyser using 1,5-diphenylcarbazide.

    Total Organic Carbon in Waters

    Instrumental catalytic oxidation of organic (and inorganic) carbon and subsequent measurement of the carbon dioxide liberated by infra-red (IR) detection.  Inorganic

    Total Petroleum Hydrocarbons (TPH) in Waters by GC-FID

    Total petroleum hydrocarbons in the range C6–C40 with optional carbon banding and/or Gasoline Range Organics (GRO), Diesel Range Organics (DRO) and 

    Aliphatic/Aromatic Petroleum Hydrocarbons in Waters by GCxGC-FID

    aliphatic banding: >C5–C6, >C6–C8, >C8–C10, >C10–C12, >C12–C16, >C16–C21, >C21– C35, >C35– C44 aromatic banding: >C5–C7, >C7–C8, >C8–C10, >C10–C12, >C12–C16, >C16– C21,

    Speciated Polynuclear Aromatic Hydrocarbons (PAH) in Waters by GC-FID

    Acenaphthene; acenaphthylene; anthracene; benzo[a]anthracene; benzo[a]pyrene; benzo[b]fluoranthene; benzo[ghi]perylene; benzo[k]fluoranthene; chrysene; dibenz[ah]anthracene; fluoranthene; fluorene; indeno[123cd]pyrene; naphthalene; phenanthrene; pyrene Methodology – Liquid/liquid solvent

    Volatile Organic Compounds (VOCs) in Waters by Headspace GC-MS

    UKAS accredited: please refer to UKAS schedule for individually accredited compounds. Analysis of a water sample for volatile organic compounds by

    Semi-Volatile Organic Compounds (SVOCs) in Waters by GC-MS

    Methodology – Liquid/liquid solvent extraction of a water sample followed by determination of semi-volatile organic compounds by gas chromatography with

    Speciated Polynuclear Aromatic Hydrocarbons (PAHs) in Waters by GC-MS

    Acenaphthene; acenaphthylene; anthracene; benzo[a]anthracene; benzo[a]pyrene; benzo[b]fluoranthene; benzo[ghi]perylene; benzo[k]fluoranthene; chrysene; dibenz[ah]anthracene; fluoranthene; fluorene; indeno[123cd]pyrene; naphthalene; phenanthrene; pyrene. Liquid/liquid solvent extraction of

    Polychlorinated Biphenyls (PCB) as Aroclors in Waters by GC-MS / GC-ECD

    Results are normally expressed as Aroclor 1242. Methodology – Liquid/liquid solvent extraction of a water sample followed by the determination

    Polychlorinated Biphenyls (PCB) ICES7 Congeners in Waters by GC-MS

    ICES (International Council for the Exploration of the Sea) PCB congeners: PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, PCB180 Methodology –

    Organophosphorus (O-P) Pesticides in Waters by GC-MS

    The method includes parathion, malathion, chlorpyrifos, diazinon  plus any organophosphorus pesticides specified by the client. Methodology – Liquid/liquid solvent extraction

    Organonitrogen (O-N) Pesticides in Waters by GC-MS

    The method includes triazines plus any organonitrogen pesticides specified by the client. Methodology – Liquid/liquid solvent extraction of a water

    Organochlorine (O-Cl) Pesticides in Waters by GC-MS

    The method includes DDT and its metabolites, the so-called ‘drins’ and Lindane, plus any determinands specified by the client. Methodology

    Phenols in Waters by GC-MS

    The method includes 24 substituted phenols, including chlorophenols. Methodology – Liquid/liquid solvent extraction of a water sample followed by the

    Phenols in Waters by HPLC

    The method includes resorcinol, phenol, methylphenols, dimethylphenols, 1-naphthol and trimethylphenols. Chlorophenols are not detected by this method. Methodology – Determination by

    Asbestos Bulk ID

    Analysis of bulk samples for the presence of asbestos as defined by The Control of Asbestos Regulations (2012). The minerals

    Water Absorption Test

    Asbestos board and cement are distinguished by density according to their percentage weight increase when saturated with water. A weight

    Identification and Quantification of Asbestos

    Stage 1 – Qualitative – presence or absence of asbestos in soil Identification of ACM and/or free fibrous bundles in

    Volatile Organic Compounds (VOCs) in Air by Automated Thermal Desorption GC-MS

    Volatile organic compounds (VOCs) are determined by automated thermal desorption followed by gas chromatography using mass spectrometric detection (ATD-GC-MS). Banded

    Sample Preparation

    In-house method based on EN 15443:2011 Solid Recovered Fuels – Methods for the preparation of the laboratory sample.  Particle size

    Ash Content

    Ash at 550oC In-house method based on EN 15403:2011 Solid Recovered Fuels – Determination of ash content.  The proportion by

    Sulphur, Fluorine, Chlorine, Bromine and Iodine

    Sulphur, fluorine, chlorine, bromine, iodine In-house method based on EN 15408:2011 Solid Recovered Fuels – Methods for the determination of

    Fixed Carbon

    Calculation using ash and volatile matter results.

    Oxygen by Difference

    Calculation using ash and elemental analysis results.

    Volatile Matter

    Volatile matter In-house method based on EN 15402:2011 Solid Recovered Fuels – Determination of the content of the volatile matter. 

    Biomass by Dissolution

    Biomass In-house method based on EN 15440:2011 Solid Recovered Fuels – Methods for the determination of biomass content.  Selective dissolution

    CHN Elemental Analysis

    Carbon, Hydrogen, Nitrogen In-house method based on EN 15407:2011 Solid Recovered Fuels – Methods for the determination of carbon (C),

    Bulk Density

    Bulk density In-house method based on EN 15401:2010 Solid Recovered Fuels – Determination of bulk density.  A weighed cylindrical container

    Particle Size Distribution

    Particle size distribution In-house method based on EN 15415-1:2011 Solid Recovered Fuels – Determination of particle size distribution – Part

    Moisture Content

    Moisture content In-house method based on CEN/TS 15414-2:2010 Solid Recovered Fuels – Determination of moisture content using the oven dry

    Gross Calorific Value (Higher Heating Value) & Net Calorific Value (Lower Heating Value)

    Gross and Net Calorific Value. In-house method based on EN 15400:2011 Solid Recovered Fuels – Determination of calorific value.  Gross

    Determination of Trace Elements

    Including arsenic, barium, beryllium, cadmium, cobalt, chromium, copper, mercury, molybdenum, manganese, nickel, lead, antimony, selenium, thallium, vanadium, zinc In-house method

    Major Elements

    Including aluminium, calcium, iron, potassium, magnesium, sodium, phosphorus, silicon, titanium. In-house method based on EN 15410:2011 Solid Recovered Fuels –