Determination of Toxic Organic Chemicals In Natural Waters, Sediments and Soils

Determination and Analysis

T. R. Crompton

• Publisher: Academic Press
• Year: 2019
• Print ISBN: 9780128158562
• eBook ISBN: 9780128165300
• Topic: Biowissenschaften
• Subtopic: Umweltwissenschaft

Determination of Toxic Organic Chemicals in Natural Waters, Sediments and Soils: Determination and Analysis reviews the latest techniques for the determination and assessment of both current and emerging organic compounds in a range of important environmental contexts. A wide range of organic compounds in non-saline waters are discussed in the opening chapters, including hydrocarbons, surface active agents and volatile organic compounds. This is followed by multiorganics, pesticides and organometallic compounds in non-saline waters. Organic compounds in aqueous precipitation are then explored before the book goes on to discuss compounds in soils, including extraction techniques, insecticides, herbicides and fungicides, and organometallic compounds.Finally, the concluding chapters focus on compounds in sediments, providing readers with the latest information in the field and supporting them as they address the important issue surrounding organic material throughout ecosystems.- Highlights the latest methods for analyzing a wide range of organic compounds- Supports researchers by providing detailed information across a range of ecosystems- Includes detailed guidance for assessing complex mixtures of organic compounds in the environment

Chapter 1

Hydrocarbons in nonsaline waters

Abstract

The identification procedure for oils in natural water samples can be divided into three stages: (1) isolation of the hydrocarbon components from the pollutant sample; (2) identification of the same in terms of the petroleum product, for example crude oil, petroleum and gas oil; (3) identification of the specific source of pollution, such as an individual tanker, tank truck, factory or domestic fuel tank. Stage (2), a general classification of the oil is often satisfactorily achieved by gas chromatographic techniques possibly coupled with mass spectrometry or infrared spectroscopy applied to a sample of the oil pollutant. Stage (3), the true identification, invariably requires samples from potential sources for comparison with the pollutant.

Keywords

gas chromatography; oil spillage; sampling; fingerprint; head space analysis; degassing technique

Chapter Outline

• 1.1 Aliphatic hydrocarbons 1
  • Head space analysis 3
  • Gas stripping methods 4
  • Gas chromatography 5
  • High-performance liquid chromatography 7
  • Infrared spectroscopy 7
  • Thin-layer chromatography 10
  • Fluorescence techniques 11
  • Paper chromatography 12
  • Sampling 12
  • Oil spillages 13
  • Metals in spillage oils 16
  • Continuous monitoring of oil slicks 16
• 1.2 Aromatic hydrocarbons 17
  • Gas chromatography 17
  • Column chromatography 18
  • Spectrophotometric method 18
  • Infrared spectrometry 18
  • Ultraviolet spectroscopy 19
  • Polycyclic aromatic hydrocarbons 21
  • Gas chromatography 22
  • High-performance liquid chromatography 24
  • Thin-layer chromatography 25
  • Fluorescence spectrometry 26
  • Miscellaneous 26
• References 28

1.1 Aliphatic hydrocarbons

The identification procedure for oils in natural water samples can be divided into three stages:

1. 1. Isolation of the hydrocarbon components from the pollutant sample.
2. 2. Identification of the same in terms of the petroleum product, for example crude oil, petroleum and gas oil.
3. 3. Identification of the specific source of pollution, such as an individual tanker, tank truck, factory or domestic fuel tank.

Stage (2), a general classification of the oil is often satisfactorily achieved by gas chromatographic techniques possibly coupled with mass spectrometry or infrared spectroscopy applied to a sample of the oil pollutant. Stage (3), the true identification, invariably requires samples from potential sources for comparison with the pollutant.

This is often attempted again using gas chromatography, by comparison of the resulting chromatograms, but in a less satisfactory and confident manner. Generally, when the comparisons of chromatograms are reasonably similar, the perpetrator of the pollution accepts liability in the case of accumulated circumstantial and scientific evidence and introduces the recommended remedial measures.

Existing gas chromatographic techniques can, in the majority of cases, classify petrol, paraffin, light fuel oils, intermediate fuel oils and, with less ease, lubricating, transformer and cutting oils. Higher boiling products with little volatility are not amenable to conventional gas chromatographic techniques, and recourse has to be taken to other techniques such as the use of capillary columns or non-gas liquid chromatography (GLC) techniques.

Techniques other than gas chromatography or, more commonly, combinations of techniques have been used to characterise oil spills. These include analytical determination such as the infrared spectra, asphaltene and paraffin contents, that provide a general classification of the pollutants (crude oils, fuel oils, oil sludges, etc.) and others, such as the Ni/V ratios, sulphur content and chromatographic profiles, that permit, by comparison with reference samples, their precise identification.

However, another approach involving only one analytical technique, but increasing the number of parameters considered, has been emphasised recently for analysis, that is infrared spectroscopy–gas chromatography. In these cases a multiparametric profile is used for identification, instead of a combination of different analytical determinations and pattern recognition techniques have, often, been applied to improve the diagnostic performance.

The main requirements that must fulfil these fingerprinting parameters besides their specificity are that they must remain unaltered during the weathering processes affecting the pollutant, namely by evaporation, solution, photooxidation and biodegradation. In consequences, both conditions, specificity and stability, need to be investigated in order to evaluate the reliability and the usefulness of any proposed method.

Vos et al. [1] have carried out a detailed study of the analysis of oil-contaminated groundwater to ascertain the rate of filtration of oil components and the effects of their biodegradation under conditions very close to those in a natural aquifer. Large-scale lysimeter experiments are reported in a sand-dune area where the groundwater level could be adjusted with an external overflow device. Details are given of hydrocarbon concentrations determined by adsorption onto Amberlite XAD-4 resins and investigations using chromatography, mass spectroscopy, high-resolution gas chromatography, infrared spectroscopy and ultraviolet spectroscopy.

Matsumoto and Hanya [2] compared the principal hydrocarbons from polluted river water and unpolluted surface water in Japan. The presence of aqualane, and unresolved mixture of hydrocarbons, and n-alkanes with an even number of carbon atoms was related to the occurrence of artificial hydrocarbons (fossil fuels and industrial products) while the occurrence of n-alkanes with an odd number of carbon atoms in unpolluted waters was due mainly to the presence of algae and higher aquatic plants.

Peitscher [3] detected and identified traces of oil on surface water. Samples of oil films on surface water were collected with a cloth made of polyester fabric. The cloth was fixed to telescopic rods, so that less accessible sites could be reached and it was kept on the oil interface for periods ranging from several minutes to 1 hour depending on the amount of oil. The adsorbed oil was extracted and analysed by infrared spectroscopy. Investigation by techniques including gas chromatography and mass spectroscopy facilitated identification of the sources of pollution, which could be confirmed by direct comparison of infrared spectra. Differences between spectra for five different types of oil were distinct for a film thickness of 0.2 mm but less distinct for a film thickness of 0.1 mm.

Various techniques for the determination of aliphatic hydrocarbons are now reviewed.

Head space analysis

Khazal et al. [4] and Drodz and Novak [5] examined and compared the methods of headspace gas and liquid extraction analysis, comparing the gas chromatography of samples of gaseous liquid-extract phases withdrawn from closed equilibrated systems and involving standard addition quantitation, for the determination of trace amounts of hydrocarbons in water. The liquid extraction method [6] is more accurate but it yields chromatograms with an interfering background due to the liquid extractant. The sensitivity of determination of volatile hydrocarbons in water is roughly the same for each method, and the concentration amenable to reliable determination amounting to tens of µg L⁻¹ on a packed column with a flame ionisation detector.

Drodz et al. [7] examined the reliability and reproducibility of qualitative and quantitative headspace analyses of parts per billion of various aliphatic and aromatic hydrocarbons in water using capillary column gas chromatography utilising a simple all-glass splitless sample injection system. They examined the suitability of the standard addition method for quantitative headspace gas analysis for concentrations in the condensed phase up the hundreds of parts per billion.

The headspace method of analysis is less accurate but more sensitive than methods based on liquid extraction. With this method an equilibration time of 10 minutes is adequate for equilibrium between the water sample and the headspace to be achieved.

Various other workers [8,9] have studied the application of headspace analysis to the determination of hydrocarbons in water. McAucliffe [10] determined dissolved individual hydrocarbons in 5 mL aqueous samples by injecting up to 5 mL of the headspace. For petroleum oils, which contain numerous hydrocarbons, very much larger aqueous samples are required. The percentage of hydrocarbons in the gaseous phase, after water containing the hydrocarbons in solution was equilibrated with an equal volume of gas, was found to be 96.7%–99.2% for most C₃–C₈ alkenes. In the case of benzene and toluene the values were 18%, 5% and 21.0% respectively, indicating that the lower aromatic hydrocarbons may be less amenable to the technique.

Gas stripping methods

Swinnerton and Linnenbom [11] were the first to examine the applicability of gas stripping methods to the determination of hydrocarbons in water. They determined C₁–C₆ hydrocarbons by stripping them from water with a stream of helium.

After gas stripping, the hydrocarbons can be passed directly to a gas chromatograph or, to increase sensitivity, trapped in a cold trap and then released into the gas chromatograph. Alternatively, ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface
• Chapter 1. Hydrocarbons in nonsaline waters
• Chapter 2. Oxygen-containing compounds in nonsaline waters
• Chapter 3. Halogen-containing compounds in nonsaline waters
• Chapter 4. Nitrogen compounds in nonsaline waters
• Chapter 5. Phosphorus containing compounds in nonsaline waters
• Chapter 6. Sulphur-containing compounds in nonsaline waters
• Chapter 7. Surface active agents in nonsaline waters
• Chapter 8. Volatile organic compounds in nonsaline waters
• Chapter 9. Multiorganic compounds in nonsaline waters
• Chapter 10. Pesticides and herbicides in nonsaline waters
• Chapter 11. Miscellaneous organic compounds in nonsaline waters
• Chapter 12. Organometallic compounds in nonsaline waters
• Chapter 13. Organic compounds in aqueous precipitation
• Chapter 14. Organic compounds in soil, solvent extraction
• Chapter 15. Determination of noninsecticidal compounds in soil
• Chapter 16. Determination of insecticides and herbicides in soil
• Chapter 17. Determination of organometallic compounds in soils
• Chapter 18. Determination of organic compounds in sediments
• Chapter 19. Organometallic compounds in sediments
• Index