Detection of chlordecone by liquid chromatography with tandem mass spectrometry

Abstract

Detection of chlordecone by liquid chromatography with tandem mass spectrometryChlordecone (decachlorooctahydro-1,3, 2-metheno-2H-cyclobuta [c,d]pentalen-2-one) is an organo-chlorine insecticide that was formerly used extensively. 1The compound is a member of the persistent organic pollutants that exhibit remarkably long half-lives in the environment, and it is well known that chlordecone shows various toxicities such as arrest of sperm maturation, 2 blocking of reproductive function, 3 and a variety of estrogen-like effects on the female reproductive system in birds and mammals. 4 Therefore, it is very important to understand the chlordecone concentration in various environments.In general, chlordecone is determined by gas chromatography with electron capture detection (GC/ECD). 5 However, in order to apply an appropriate method to the analysis of chlordecone in various environmental media and matrices, it is important to develop a novel analytical method to complement the methods based on GC. We have developed an analytical method for chlordecone using liquid chromatography with tandem mass spectrometry (LC/MS/MS). The LC/ MS/MS technique has the potential to simplify the analytical pretreatment, and to provide rapid confirmation of chlordecone in environmental samples.Chlordecone was purchased from Wako Pure Chemical Industries (Osaka, Japan). A stock solution at a concentration of 1000 mg/mL was prepared by dissolution of chlordecone in methanol. The solutions were stored in the dark. Working standards were prepared on a daily basis by dilution of the stock solution with methanol. Chlordecone-13 C 8 , used as an internal standard, was obtained from Cambridge Isotope Laboratories Inc. (Andover, USA). Five mL of the internal methanol solution (0.1 mg/mL) was added to the chlordecone standard solutions (1.0 mL).The LC/MS/MS analysis was performed using a MDS-Sciex API 3000 system (Applied Biosystems). Ionization of chlordecone was achieved by electrospray (ESI-MS) in the negative ion mode. All the interface parameters were optimized by infusing a standard solution (0.1 mg/mL) of the analytes. The final electrospray conditions were as follows: nitrogen curtain gas, 6 psi; ion spray voltage, À4500 V; declustering potential, À81 V. The full-scan single-quadrupole mass spectra were obtained in the range m/z 400-700 at a scan rate of 1 scan/s. The product-ion mass spectrum of the ion (m/z 507) was acquired in the range m/z 10-520 at a scan rate of 1 scan/s. The collision energies were À28 and À32 eV for chlordecone and the internal standard, respectively. The LC/MS/MS acquisition was performed in the multiple reaction monitor (MRM) mode by following the reactions m/z 507 ! 427, characteristic of chlordecone, and m/z 515 ! 434, characteristic of the internal standard, chlordecone-13 C 8 . Liquid chromatography was conducted using an 1100 series (Agilent) separation module interfaced to the API 3000 system. A Develosil C30-UG-5 column (Nomura Chemicals; 5 mm particle size, 2.0 mm i.d. Â 150 mm) was used for the LC sepa...

Determination of Kepone and Its Metabolite in Water and Soil by High-Performance Liquid Chromatography–Mass Spectrometry

“…Kepone is reported to form its hydrate in water, and hence the hydrate is determined by HPLC (Harless et al 1978) (Figure S4, Supplemental Content) and electrospray ionization (Moriwaki and Hasegawa 2004). Kepone and kepone alcohol were separated (Figure 1) with a total analysis time of 7 min.…”

“…Detailed examination of the total ion chromatogram (TIC) produced in methanol revealed several noteworthy features. Although Moriwaki and Hasegawa (2004) developed a HPLC-MS method with a limit of detection (LOD) of 0.007 ng=mL, the formation of the hemiketal was not considered ( Figure S2, Supplemental Content). Therefore, acetonitrile was employed for the analysis (Harless et al 1978).…”

“…George, King, and Claxton (1986) reported that kepone may be determined by high-performace liquid chromatography (HPLC), which tolerates higher sample loading and may avoid sample degradation (Harless et al 1978;Cairns, Siegmund, and Doose 1982). In addition, HPLC-mass spectrometry (MS) typically exhibited higher sensitivity than GC-MS (Moriwaki and Hasegawa 2004), although the analysis may be affected by formation of a methanolic hemiketal. Moriwaki and Hasegawa (2004) developed an HPLC-ESI-MS method for…”

“…In addition, HPLC-mass spectrometry (MS) typically exhibited higher sensitivity than GC-MS (Moriwaki and Hasegawa 2004), although the analysis may be affected by formation of a methanolic hemiketal. Moriwaki and Hasegawa (2004) developed an HPLC-ESI-MS method for…”

“…Recently, the method was reevaluated by our group for real sample analysis. Unexpectedly, in addition to the ion at m=z 507 [M þ H 2 O-H] - (Moriwaki and Hasegawa 2004;Fariss et al 1982), an ion at m=z 521 [M þ MeOH-H] -( Figure S1, Supplemental Content) was also observed by HPLC-MS when kepone was eluted in methanol=water. The methanolic adduct was also reported by Harless et al (1978).…”