Introduction

Phthalic acid diesters (PAEs) are widely spread in the environment. During the past years, interest in monitoring this class of industrial chemicals has increased. Several methods have been developed for their determination in a very broad range of matrices, including water (drinking water, surface water, waste water), soil, sediment, sludge, dust, indoor and outdoor air, and biota (vegetation, milk, fish, etc.). In this chapter an overview is given of different techniques used for the analysis...

Water

Jin et al. 7 reported first-order aqueous photolysis rates for DBP and DEHP of 0.23 and 0.9 h-1, corresponding to half-lives of 3 and 0.75 h, respectively. The PDEs were present in a surface micro-layer in mg L-1 quantities. The reaction was dependent upon light intensity and oxygen. The rate was stimulated by the presence of TiO2 and H2O2 and the optimum pH was 6.0. The results under artificial light (72,000 lux) were essentially the same as with natural sunlight (83,000 lux). The...

Dimethyl Phthalate DMP

The assigned distributions for the concentration of DMP in each medium used for the exposure assessment are summarized in Table 2. These concentration distributions are obtained from the report prepared for the American Chemistry Council 13 . For DMP, few data are available for food. Measurements of DMP in fish, milk, and vegetables are all reported as not detected. One of the larger studies of phthalate ester concentrations in food 14 indicated that the presence of DMP was evaluated, but was...

Diethyl Phthalate DEP

The assigned distributions for the concentration of DEP in each medium used for the exposure assessment are summarized in Table 3. These concentration distributions are obtained from the report prepared for the American Chemistry Council 13 . For DEP, data are not available for infant formula or breast milk. As shown in Table 3, the median estimated daily intake of DEP for each group in mg kg-1 d-1 is adults (2.5), teens (3.0), children (5.7), and toddlers (10.6). The estimated intake for...

EQC Level I Modelling

EQC Level I modelling has been performed for the 22 phthalate esters listed in Table 1 for which physical-chemical properties have previously been estimated (Table 3). Level I EQC model results indicate that under equilibrium, steady state conditions, with no reaction, the vast majority of phthalates released will reside in soil, sediment or water with over 99 being distributed to these three media (Table 6). The low vapour pressures ensure that only small percentages partition to air....

Degradation of Phthalate Metabolites

The metabolic pathways for PDE biodegradation have been reviewed 1 . There is abundant evidence that the pathway of PDE metabolism, at least by microorganisms, is via a stepwise hydrolysis of the two ester bonds, first giving the monoester plus the free alcohol, followed by hydrolysis of the second ester bond to give PA and alcohol. The PA is degraded aerobically via hydroxylation and decarboxylation to give protochatechuic acid, which is further degraded to carbon dioxide through either ortho...

Air

Direct photolysis probably does not play a major role in the atmospheric degradation of PDEs 1 . However, indirect photolysis by hydroxyl radical oxidation may contribute appreciably to overall fate. Staples et al. 1 calculated a range of air oxidation half-lives for PDEs based on the air oxidation program (AOP) of Atkinson 2 and a range of hydroxyl radical concentrations from 3 x 105 to 3 x 106 molecule cm-3. The atmospheric half-lives of a number of PDEs have been recalculated with an updated...

Solubility Influence on Toxicity

For an in-depth discussion of the physico-chemical properties of phthalate esters the reader is referred to Chapter 3 of this handbook. Perhaps most notable about phthalate esters in regards to their physico-chemical properties is that they demonstrate a solubility cut-point, and like many organic chemicals the aquatic toxicity of phthalate esters is strongly influenced by water solubility. As shown in Table 1, phthalate esters have solubilities ranging from 5200 mg L to less than 1 x 10-7 mg...

Primary Versus Ultimate Degradation

The degradation data that are of use for modeling and for evaluation of environmental persistence are the pseudo-first-order disappearance rates of the PDEs. Environmental fate models utilize physical-chemical properties such as water solubility and vapor pressure to calculate the partitioning behavior of a chemical in the environment. These physical chemical properties differ greatly between the parent PDE and its degradation products. The overall decrease in concentration of the parent...

Native Soil

The principle source of PEs to soils that are not amended with sewage sludge is atmospheric deposition. Several studies have reported atmospheric deposition rates of PEs in different locations (Table 6). Based on these data an atmospheric deposition of 1 gdrym-2 d-1 is typical for DMP, DEP, DBP and DEHP. Given this estimate and assuming an average mixing depth for non-agricultural soil of 0.05 m and a soil density of 1700 kgdry m-3 65 and ignoring the mitigating role of biodegradation the...

Solid Phase Biodegradation

There have been numerous reports of the growth of microbes on the surface of fabricated PVC plastic materials. This susceptibility of PVC to biodeterioration is principally due to the presence of biodegradable plasticizers in the polymer 83 . Webb et al. 83 isolated and identified a large number of fungi that colonized the surface of dioctyl adipate (DOA)-plasticized PVC. The most active strains were able to utilize the plasticized PVC as a sole source of carbon, produced an extra-cellular...

Analytical Procedure for the Determination of Phthalates in Fish

Depending on the type of fish and available sample size, the fish samples can be analysed as whole fish, as fillet (muscle with skin removed) or the analysis can be performed on specific organ samples (liver, stomach). For diet studies, the fillet sample represents the edible part of the fish. For contamination studies, whole fish samples or organ analyses give relevant information. Due to their lipophilic character, phthalates accumulate in the fat. The analytical methods for the determination...

Sample Preparation Methods for Phthalic Acid Mono Esters

Phthalic acid monoesters are more polar than phthalates and therefore the sample preparation methods must be adapted. For the determination of monoesters in blood, plasma and urine samples, several methods are described in the literature 8-10, 12, 13, 17, 18 . For the determination of monoesters in environmental samples, only limited data are available. Suzuki et al. 14 used solid-phase extraction on polymeric phase disks (styrene divinylbenzene) for the determination of monoesters in...

Air Water Partition Coefficient

The equilibrium distribution of a substance between air and water is known as the air-water partition coefficient (KAW) and is used to indicate the tendency of a substance to escape from water to air. It is noteworthy that volatility of the pure substance is characterized by vapour pressure. Volatility from water is expressed as Kaw and for volatilisation from organic media KOA is preferred. KAW is more usually measured in the form of a Henry's law constant (H, Pa mol m 3), which can also be...

Liquid Liquid Extraction LLE

The extraction of relatively large volumes of water samples (1-2 L) with an apolar non-miscible solvent is the most straightforward method for the extraction of phthalates from aqueous samples. Good extraction recoveries are obtained by using dichloromethane, cyclohexane or hexane 22 . The ratio of the volume of the water sample to the volume of the organic solvent should be smaller than 20. Higher ratios will still result in high recovery for the high-molecular weight phthalates (logKow 7.73...

Uses of Phthalate Esters

Uses of phthalate esters can be broadly split into three general categories - vinyl plasticizers, plasticizers for non-PVC polymers and other minor specialized applications. In the United States, DEHP, DINP and DIDP account for 52.2 of phthalates consumed. Linear phthalates account for 21.4 of the consumption and the 26.4 balance of US consumption includes all other phthalates esters 4 . Table 1. Physical properties of phthalate esters Abbreviation Phthalate Formula CAS No. EINECS No. Molecular...

Analytical Procedure for the Determination of Phthalates in Milk or Edible Oils and

For the determination of phthalate in milk samples the following method was developed 7 . Milk samples are first homogenised by shaking. Milk powders are dissolved in water (1 g 10 mL).Approximately 5 g milk sample is then extracted with 20 mL of a 1 1 cyclohexane acetone mixture in a 40 mL I-Chem vial. The vials are shaken on a shaking machine for 30 min. After completion, the vials are centrifuged and the supernatant is transferred to a pre-weighed I-Chem vial. The solvent is evaporated under...

EQC Level III Modelling

Level III modelling is useful for determining how the medium of release affects environmental fate. Level III fugacity calculations allow non-equilibrium conditions to exist between connected media as steady state, and illustrate important transport and transformation processes. The tendency of chemicals to migrate between media can be assessed by modelling emissions to each individual medium and calculating the amount present at steady state. Table 7 shows the amount of chemical present in...

Comparison to Other Studies

Several other studies have evaluated human exposure to DEHP 2,4, 9,16,17, 20-23 .Table 10 presents a comparison of the results of these studies with those of the present study. David 16 used the CDC data to back-calculate the intake of each of the phthalate esters and the results are shown in Table 10 for DEHP. As shown in Table 10, the calculated geometric mean intake is approximately an order of magnitude less than the estimated median intake in the present study and the 95th percentile...

References

Staples CA, Adams WJ, Parkerton TF, Gorsuch JW, Biddinger GR, Reinert KH (1997) Aquatic toxicity of eighteen phthalates esters. Environ Toxicol Chem 15 875 - 981 2. Parkerton TF, Konkel WJ (2000) Application of quantitative structure - activity relationships for assessing the aquatic toxicity of phthalate esters. Ecotoxicol Environ Saf 45 61-78 3. Adams WJ, Heidolph BB (1985) Short-cut chronic toxicity estimates using Daphnia magna. Aquatic Toxicology and Hazard Assessment Seventh Symposium,...

Algae

Chronic toxicity test results on algae are shown in Table 4. Algal assays that have at least a 72-h duration are considered chronic assays 13 because the duration Table 2. Select EC LC50 values for the acute aquatic toxicity of phthalate esters, as presented in staples et al. 1 Test species Phthalate Fresh salt Measured Test duration Test endpoint EC or LC50 Ref. ester (F S) nominal or criteria (mg L) Selenastrum capricornutum S. capricornutum Scenedesmus subspicatus Phthalate esters > C6 S....

Octanol Water Partition Coefficient

The equilibrium distribution of a substance between water and octanol is known as the octanol-water partition coefficient and is often used to predict the expected partitioning in the environment between water and animal plant lipids and water and sediment soil organic matter. There is an abundance of correlations between KOW and measured environmental partition coefficients (e.g. bioconcentration factors, see review by Gobas et al. 46 soil sediment organic carbon-water partition coefficients,...

Solubility in Water

A declining trend in solubility in water is observed with increasing alkyl chain length or molar volume (Table 3 and Fig. 1). The phthalates have a remarkably large variation in their solubility in water with DMP being moderately soluble at 5gL-1 and DTDP having an estimated solubility some 11 orders of magnitude lower at 7 x 10-11 g L-1. The variability in reported solubility data (Table 2) tends to increase as the measured solubilities decrease, mainly as a result of increased difficulty of...

Passive Sorptive Sampling of Phthalates in

Passive sampling is a very suitable technique for the measurement of air quality in indoor and working environment 52 . For passive sampling, a sorbent is put in a holder. This may be placed in a specific place in the room or used as a personal sampler. Sampling is performed over several hours or days and concentrations are expressed as time weight averages (TWA). The (ad)sorbed solutes are desorbed with a suitable solvent and the extract is analysed. Recently, solid-phase micro-extraction...

EQC Level II Modelling

Persistence in the environment can be operationally defined as the overall residence time at steady state in a multimedia environment 66 . Level II and Level III calculations can both give estimates of persistence. Level II calculations give a preliminary estimate of persistence based on equilibrium partitioning, whereas Level III provides a more sophisticated albeit data-intensive estimate of persistence that accounts for medium of discharge and intermedia transport rates. A Level II approach...

Estimating Persistence and Long Range Transport Potential with the TaPL3 Model

The TaPL3 model, which was developed specifically for estimating environmental persistence and long-range transport (LRT) potential 66,68 , is identical in properties to EQC, but it is set to mimic a closed system, from which no advec-tive losses occur (via air or water flows). By considering only irreversible losses, a conservative estimate of persistence is obtained that may better reflect the removal of chemicals from the environment as a whole. Environmental persistence is evaluated by...

Analysis of Total Phthalate Concentrations in

For the determination of total phthalate concentrations (gaseous + aerosols + particulates), sampling on a sorbent tube is used. Most widely used adsorbents are activated carbon, porous polymers like Tenax (2,6-diphenylphenylene oxide polymer) and resins (XAD-2) 38-47 .Recommended methods for the sampling and analysis of phthalates (OSHA CIM, OSHA 104, NIOSH 5020) also include trapping of the phthalates present as aerosols or in the vapour phase on a combination of a polyurethane foam (PUF)...

Solid Phase Extraction SPE

In comparison with liquid-liquid extraction, the amount of solvent can be reduced drastically by using solid-phase extraction. The water sample (100 mL to 2 L) is passed through an apolar sorbent and the phthalates are concentrated on the sorbent. The most widely used sorbent for enrichment of phthalates is octadecyl silicagel (ODS, C18). For elution, different solvents can be used (dichloromethane, ethyl acetate, etc.). Solid-phase extraction can be performed with classical cartridges...