The electron capture detector was reported for detection of phthalates in mineral
water, river water, and bottled water (Eskandarpour and Sereshti 2018) with similar
sensitivities to a flame ionization detector.
15.3.2 High-Performance Liquid Chromatography
High-performance liquid chromatography is selective, sensitive, accurate, and reproducible, and it is particularly suitable for the analysis of difficult-to-volatile analytes,
so it has a very wide application in analysis of the organic compounds. The high
molecular weight phthalates have a boiling point higher than 300
C, and it is
difficult to be effectively volatile under the normal inlet port temperature of a gas
chromatograph. So it is preferable to analyze them by high-performance liquid
chromatography. Even low molecular weight phthalates have satisfactory sensitivities. The benzene ring and double bond in the chemical structure of phthalates make
them be easily detected by an ultraviolet detector or a diode array detector. Of
course, a mass spectrometer is the best choice for phthalates detection. The most
often used separation columns are octadecylsilane chemically bonded silica column
(Yang et al. 2018a, b; Santana-Mayor et al. 2018) and octylsilane chemically bonded
silica column (Liang et al. 2008). The mobile phase is generally composed of
methanol–acetonitrile and water–formic acid solution.
Yang et al. (2018b) determined 15 phthalates in tap water, bottled water, and river
water by high-performance liquid chromatography after solidified floating organic
drop microextraction. The separation was performed on an octadecylsilane column
(250 Â 4.6 mm, 5 μm) and detected by an ultraviolet detector. The method’s linear
ranges were 0.1–100 μg/L, and the limits of detection were 0.013–0.158 μg/L. The
recovery rates of the method were 86.8–119% with the relative standard deviations
of 3.0–13.7%. Luo et al. (2014) established a high-performance liquid chromatography with diode array detection for the analysis of five phthalates in tap water and
bottled water. ZORBAX SB-octadecylsilane column was used for separation with
methanol–water as mobile phase. The detection wavelength was 226 nm, and the
recoveries were 87.7–100.9%. Octylsilane column was used as separation column,
and acetonitrile–water was used as mobile phase has been reported for analysis of
phthalates in water samples too (Liu et al. 2015b).
The sensitivity and qualitative ability of ultra-performance liquid chromatography coupled with tandem mass spectrometry are much higher than those of ultraviolet detection-based conventional liquid chromatography and are suitable for trace
analysis of phthalates. However, the instrument is quite expensive, and the maintenance cost is high as well. Santana-Mayor et al. (2018) concentrated and cleaned-up
14 phthalates from mineral water, pond water, and wastewater samples by using
magnetic-micro-dispersive solid-phase extraction technique; then the separation was
performed on an octadecylsilane column (50 mm  2.1 mm, 1.7 μm), and finally
detected by tandem mass spectrometer; dinbutyl phthalate-d4 was used as an internal
standard. The method had recoveries varying from 70% to 120%, and the limits of
15 Analytical Methods for Phthalates in Water Samples
557
water, river water, and bottled water (Eskandarpour and Sereshti 2018) with similar
sensitivities to a flame ionization detector.
15.3.2 High-Performance Liquid Chromatography
High-performance liquid chromatography is selective, sensitive, accurate, and reproducible, and it is particularly suitable for the analysis of difficult-to-volatile analytes,
so it has a very wide application in analysis of the organic compounds. The high
molecular weight phthalates have a boiling point higher than 300
C, and it is
difficult to be effectively volatile under the normal inlet port temperature of a gas
chromatograph. So it is preferable to analyze them by high-performance liquid
chromatography. Even low molecular weight phthalates have satisfactory sensitivities. The benzene ring and double bond in the chemical structure of phthalates make
them be easily detected by an ultraviolet detector or a diode array detector. Of
course, a mass spectrometer is the best choice for phthalates detection. The most
often used separation columns are octadecylsilane chemically bonded silica column
(Yang et al. 2018a, b; Santana-Mayor et al. 2018) and octylsilane chemically bonded
silica column (Liang et al. 2008). The mobile phase is generally composed of
methanol–acetonitrile and water–formic acid solution.
Yang et al. (2018b) determined 15 phthalates in tap water, bottled water, and river
water by high-performance liquid chromatography after solidified floating organic
drop microextraction. The separation was performed on an octadecylsilane column
(250 Â 4.6 mm, 5 μm) and detected by an ultraviolet detector. The method’s linear
ranges were 0.1–100 μg/L, and the limits of detection were 0.013–0.158 μg/L. The
recovery rates of the method were 86.8–119% with the relative standard deviations
of 3.0–13.7%. Luo et al. (2014) established a high-performance liquid chromatography with diode array detection for the analysis of five phthalates in tap water and
bottled water. ZORBAX SB-octadecylsilane column was used for separation with
methanol–water as mobile phase. The detection wavelength was 226 nm, and the
recoveries were 87.7–100.9%. Octylsilane column was used as separation column,
and acetonitrile–water was used as mobile phase has been reported for analysis of
phthalates in water samples too (Liu et al. 2015b).
The sensitivity and qualitative ability of ultra-performance liquid chromatography coupled with tandem mass spectrometry are much higher than those of ultraviolet detection-based conventional liquid chromatography and are suitable for trace
analysis of phthalates. However, the instrument is quite expensive, and the maintenance cost is high as well. Santana-Mayor et al. (2018) concentrated and cleaned-up
14 phthalates from mineral water, pond water, and wastewater samples by using
magnetic-micro-dispersive solid-phase extraction technique; then the separation was
performed on an octadecylsilane column (50 mm  2.1 mm, 1.7 μm), and finally
detected by tandem mass spectrometer; dinbutyl phthalate-d4 was used as an internal
standard. The method had recoveries varying from 70% to 120%, and the limits of
15 Analytical Methods for Phthalates in Water Samples
557