The Determination of Galaxolide in Water Samples with SPME Coupled with GC-MS

Described is a solid-phase microextraction-gas chromatography mass spectrometric procedure for the determination of galaxolide (HHCB) in water solution samples. In which 100 μm PDMS coated fiber were used. From the optimization experiments of SPME, we found the direct sampling is necessary. The extraction time and temperature were 40min and 35°C, respectively. the salinity of the solution almost has no effect on the extraction efficiency and pH=7.0 was suitable for the extraction of HHCB. The method were applied to the urban sewage and river water respectively and found the content of HHCB in the urban sewage is 286ng/L, while those in river water below limit of quantification.

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LC–MS-MS Method for the Determination of Antidepressants and Benzodiazepines in Meconium

Journal of Analytical Toxicology ◽

10.1093/jat/bkaa012 ◽

2020 ◽

Vol 44 (6) ◽

pp. 580-588

Author(s):

A López-Rabuñal ◽

E Lendoiro ◽

M Concheiro ◽

M López-Rivadulla ◽

A Cruz ◽

...

Keyword(s):

Extraction Efficiency ◽

Solid Phase ◽

Gradient Methods ◽

Reversed Phase ◽

Process Efficiency ◽

Limit Of Quantification ◽

Mode 2 ◽

Positive Mode ◽

Compound Method

Abstract An LC–MS-MS method for the determination of 14 benzodiazepines (BZDs) (alprazolam, α-hydroxyalprazolam, clonazepam, bromazepam, diazepam, nordiazepam, lorazepam, lormetazepam, oxazepam, flunitrazepam, 7-aminoflunitrazepam, triazolam, midazolam and zolpidem) and 15 antidepressants (ADs) (amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, norclomipramine, fluoxetine, norfluoxetine, sertraline, norsertraline, paroxetine, venlafaxine, desmethylvenlafaxine, citalopram and desmethylcitalopram) in meconium was developed and validated. Meconium samples (0.25 ± 0.02 g) were homogenized in methanol and subjected to mixed-mode cation exchange solid-phase extraction. Chromatographic separation was performed in reversed phase, with a gradient of 0.1% formic acid in 2 mM ammonium formate and acetonitrile. Two different chromatographic gradient methods were employed, one for the separation of ADs and another for BZDs. Analytes were monitored by tandem mass spectrometry employing electrospray positive mode in MRM mode (2 transitions per compound). Method validation included: linearity [n = 5, limit of quantification (LOQ) to 400 ng/g], limits of detection (n = 6, 1–20 ng/g), LOQ (n = 9, 5–20 ng/g), selectivity (no endogenous or exogenous interferences), accuracy (n = 15, 90.6–111.5%), imprecision (n = 15, 0–14.6%), matrix effect (n = 10, −73 to 194.9%), extraction efficiency (n = 6, 35.9–91.2%), process efficiency (n = 6, 20.1–188.2%), stability 72 h in the autosampler (n = 3, −8.5 to 9%) and freeze/thaw stability (n = 3, −1.2 to −47%). The method was applied to four meconium specimens, which were analyzed with and without hydrolysis (enzymatic and alkaline). The authentic meconium samples tested positive for alprazolam, α-hydroxyalprazolam, clonazepam, diazepam, nordiazepam, fluoxetine, norfluoxetine, clomipramine and norclomipramine. Therefore, the present LC–MS-MS method allows a high throughput determination of the most common BZDs and ADs in meconium, which could be useful in clinical and forensic settings.

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