goal is to develop the most selective extraction method, optimizing the extraction
conditions to exploit the chemical differences between analytes and matrix components. In the event that part of the matrix is co-extracted with the analytes, it is often
advisable to carry out a further step consisting of techniques for cleaning the matrix
from interfering co-extractives with the compounds of interest.
In fact, to obtain a selective method, it is necessary to consider in particular the
removal of the matrix components such as organic matter, lipids, waxes, sugars, or
pigments. The removal of these co-extracts must be controlled to minimize any
adverse effects that could affect the detection of the compounds of interest. Therefore, several post-extraction cleaning procedures have been developed for the
removal of the co-extracted matrix components.
Another often overlooked difficulty is the optimization of the extraction conditions of a new analytical method; it is necessary to use a relevant matrix containing
the analytes of interest. For persistent organic contaminants or for pesticides,
certified reference materials (CRM) are commercially available. However, as far as
PhACs are concerned, these materials are not available, and the development must
be based on internally produced materials. In most cases, producing internally
contaminant-free material means growing vegetables until fully harvested
(60–90 days in the case of a lettuce). This may lead to a delay in the development
of the analytical method which is not always feasible. Very often then, we resort to
the use of vegetables from organic farming [7].
This reference material thus obtained is then doped with known concentrations of
the compounds of interest in order to study the recovery tests and thus guarantee the
ability to perform a quantitative analysis of the compounds with the developed
method.
In an attempt to obtain a rapid and efficient extraction of the analytes from solid
matrices, different extraction techniques such as microwave-assisted extraction
(MAE), ultrasound solvent extraction (USE), pressurized liquid extraction (PLE),
or the most recent QuEChERS method have recently been the subject of in-depth
study, due to good efficiency and reliability. In fact, these are the extraction
techniques currently most used for the determination of PhACs in soil or plants.
They are preferred to traditional extraction methods such as Soxhlet, as they
guarantee greater contact between the solvent and the soil particles, with consequent
greater coverage of the analytes and a lower consumption of organic solvents. In
fact, the Soxhlet method involves very long extraction times with the consumption
of large quantities of organic solvents.
The analysis of PhACs is commonly performed using liquid or gas chromatography techniques, although liquid chromatography is preferred as it is more suitable
for the analysis of polar compounds.
The purpose of the chapter is to discuss all the analytical procedures used for the
extraction and analysis of pharmaceutical products and their related compounds
from plant tissues and from the soil irrigated with treated wastewater. This chapter
will describe all that is known about the analytical procedures published so far. In the
coming section, we will discuss the most popular previously reported methods for
pharmaceuticals extractions (USE, PLE, MAE, QuEChERS) from soil and plant
420
R. Manasfi et al.
conditions to exploit the chemical differences between analytes and matrix components. In the event that part of the matrix is co-extracted with the analytes, it is often
advisable to carry out a further step consisting of techniques for cleaning the matrix
from interfering co-extractives with the compounds of interest.
In fact, to obtain a selective method, it is necessary to consider in particular the
removal of the matrix components such as organic matter, lipids, waxes, sugars, or
pigments. The removal of these co-extracts must be controlled to minimize any
adverse effects that could affect the detection of the compounds of interest. Therefore, several post-extraction cleaning procedures have been developed for the
removal of the co-extracted matrix components.
Another often overlooked difficulty is the optimization of the extraction conditions of a new analytical method; it is necessary to use a relevant matrix containing
the analytes of interest. For persistent organic contaminants or for pesticides,
certified reference materials (CRM) are commercially available. However, as far as
PhACs are concerned, these materials are not available, and the development must
be based on internally produced materials. In most cases, producing internally
contaminant-free material means growing vegetables until fully harvested
(60–90 days in the case of a lettuce). This may lead to a delay in the development
of the analytical method which is not always feasible. Very often then, we resort to
the use of vegetables from organic farming [7].
This reference material thus obtained is then doped with known concentrations of
the compounds of interest in order to study the recovery tests and thus guarantee the
ability to perform a quantitative analysis of the compounds with the developed
method.
In an attempt to obtain a rapid and efficient extraction of the analytes from solid
matrices, different extraction techniques such as microwave-assisted extraction
(MAE), ultrasound solvent extraction (USE), pressurized liquid extraction (PLE),
or the most recent QuEChERS method have recently been the subject of in-depth
study, due to good efficiency and reliability. In fact, these are the extraction
techniques currently most used for the determination of PhACs in soil or plants.
They are preferred to traditional extraction methods such as Soxhlet, as they
guarantee greater contact between the solvent and the soil particles, with consequent
greater coverage of the analytes and a lower consumption of organic solvents. In
fact, the Soxhlet method involves very long extraction times with the consumption
of large quantities of organic solvents.
The analysis of PhACs is commonly performed using liquid or gas chromatography techniques, although liquid chromatography is preferred as it is more suitable
for the analysis of polar compounds.
The purpose of the chapter is to discuss all the analytical procedures used for the
extraction and analysis of pharmaceutical products and their related compounds
from plant tissues and from the soil irrigated with treated wastewater. This chapter
will describe all that is known about the analytical procedures published so far. In the
coming section, we will discuss the most popular previously reported methods for
pharmaceuticals extractions (USE, PLE, MAE, QuEChERS) from soil and plant
420
R. Manasfi et al.