Automated on-line solid-phase extraction-gas chromatography with nitrogen-phosphorus detection: determination of benzodiazepines in human plasma

Louter, A. J. H.; Bosma, E.; Schipperen, J. C. A.; Vreuls, J. J.; Brinkman, U.A.Th.

doi:10.1016/s0378-4347(96)00345-3

Cited by 48 publications

(24 citation statements)

References 14 publications

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“…Sample preparation techniques involve SPE [36,40], automated on-line SPE [34], SPME [23,24,33], on-line dialysis [37,38], direct LC analysis using restricted access extraction materials [43,44], column switching techniques [45][46][47][48], as well as liquid phase microextraction [32].…”

Section: Introductionmentioning

confidence: 99%

Development of a validated HPLC method for the determination of four 1,4‐benzodiazepines in human biological fluids

Samanidou

Pechlivanidou

Papadoyannis³

2007

J of Separation Science

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A simple and sensitive HPLC method was developed and validated for the determination of four frequently prescribed 1,4-benzodiazepines: alprazolam (ALP), bromazepam (BRZ), diazepam (DZP), and flunitrazepam (FNZ). Separation was achieved on an Inertsil C8 analytical (250 mm x 4 mm, 5 microm) column, after selective extraction of benzodiazepine drugs from biological matrices by means of SPE. Isocratic elution was performed with a mobile phase consisting of CH3COONH4, 0.05 M CH3OH, and CH3CN (33:57:10 by volume). Quantification was performed at 240 nm with mefenamic acid (6 ng/microL) as the internal standard. DSC-18 Supelco cartridges provided high absolute recoveries (81-115%). The developed method was fully validated in terms of selectivity, linearity, accuracy, precision, stability, and sensitivity. Repeatability (n = 8) and between-day precision (n = 8) revealed RSD <12%. Recoveries from biological samples ranged from 81.2 to 115%. The detection limit of the method was calculated as 3.3-10.2 ng in blood plasma and 2.6-12.6 ng in urine for 20 microL injection volume. The method was applied to spiked biological matrices. Moreover, the method was applied to real samples of urine after an oral administration.

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Section: Introductionmentioning

confidence: 99%

Development of a validated HPLC method for the determination of four 1,4‐benzodiazepines in human biological fluids

Samanidou

Pechlivanidou

Papadoyannis³

2007

J of Separation Science

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“…For a more detailed operation of the operation of the loop-type interface the reader should consult ref. [29].…”

Section: On-line Spe-gc-fid; Configuration Amentioning

confidence: 99%

“…First, an earlier reported on-line ASPEC-GC approach with a loop-type interface was tested [29]. Aliquots of the final eluate (1.0 ml) in ethyl acetate were injected at a temperature of 110 "C. It should be noted that, with this procedure, only a rough drying step was used, viz.…”

Section: Configuration A: Loop-type Interjfacementioning

confidence: 99%

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Automated derivatization for on‐line solid‐phase extraction‐gas chromatography; phenolic compounds

Louter¹,

Jones²,

Jorritsma³

et al. 1997

J. High Resol. Chromatogr.

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SummaryAn automated system for derivatization was coupled on-line with solid-phase extraction-gas-chromatography (SPE-GC). The system was optimized for the determination of phenol and chlorinated phenols in aqueous samples. The test analytes were acetylated with acetic anhydride; proper buffering of the sample was a critical factor. Next, the phenol acetates were enriched on a SPE cartridge and transferred to a GC; two approaches were studied. In the first approach, the derivatives were enriched on disposable C18 cartridges (ASPEC type) and desorbed with methyl acetate. An aliquot of the final eluate was injected on-line into the GC by means OP a loop-type interface. In the second approach, trace enrichment was performed on a 10 x 2 mm i.d. LC-type precolumn packed with polystyrenedivinylbenzene copolymer (PLRP-S). This precolumn was dried with a nitrogen purge and the phenol acetates were desorbed with ethyl acetate which was injected on-line into the retention gap of the GC under partially concurrent solvent evaporation (PCSE) conditions. The derivatization-SPE-GC system which was based on the loop-type interface has the advantage of simplicity and easy operation, the main drawback is the intpossibility to determine phenol acetates which elute prior to trichlorophenol acetates. With the derivatization-SPE-GC approach using PCSEbased desorption, even the most volatile analyte of the test series, phenol acetate, can be determined successfully. The entire procedure, including the derivatization step, was fully automated and integrated in one set-up. The analytes were detected with a flame ionization detector (FID). The precision data for the integrated on-line derivatization-SP-FID system were fully satisfactory, with RSD values of 1-12 % at the 1 ~g / l level. When a sample volume of 2.2 ml was analyzed, the detection limits for the chlorinated phenol acetates were in the 0.1-0.3 pgll range.

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“…[8][9][10][11] The representative LVI methods were a programmable temperature vaporizing (PTV) injection method [12][13][14] and a largevolume on-column injection method. 15,16 Also, other available methods were loop-type, 17,18 vapor-overflow 19,20 and concurrent solvent recondensation (CSR) 21 techniques. In the conventional PTV injection method, the sample is evaporated in the inlet, and during sample introduction the solvent can be eliminated via a split outlet, while higher boiling-point analytes are retained and subsequently transferred to the separating column in the splitless mode.…”

Section: Introductionmentioning

confidence: 99%

Application of a Novel Large-Volume Injection Method Using a Stomach-Shaped Inlet Liner in Capillary Gas Chromatographic Trace Analysis of Dioxins in Human Milk and Plasma

et al. 2007

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A newly developed large-volume injection (LVI) technique that employs a unique stomach-shaped inlet liner (SSIL) inside of a programmable temperature vaporizer was used for the determination of trace amounts of dioxins in human milk and plasma. The initial temperature and the initial dwelling time of the inlet and the kind of solvent used were found to be critical in determining the analytical sensitivity of dioxins due to the loss of these relatively volatile compounds during solvent vaporization. Human milk and plasma were purified and fractionated by pre-packed multi-layered silicagel chromatography and activated carbon silica-gel column chromatography. A 20-μL aliquot of the fraction collected from the chromatography with toluene was directly applied to the LVI system in high-resolution gas chromatography/high-resolution mass spectrometry. Excellent correlation (r > 0.97) between the values obtained by the LVI method using the SSIL device and those by the conventional regular-volume splitless injection method was obtained for PCDDs, PCDFs and non-ortho PCBs in human milk and plasma samples.

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Automated on-line solid-phase extraction-gas chromatography with nitrogen-phosphorus detection: determination of benzodiazepines in human plasma

Cited by 48 publications

References 14 publications

Development of a validated HPLC method for the determination of four 1,4‐benzodiazepines in human biological fluids

Development of a validated HPLC method for the determination of four 1,4‐benzodiazepines in human biological fluids

Automated derivatization for on‐line solid‐phase extraction‐gas chromatography; phenolic compounds

Application of a Novel Large-Volume Injection Method Using a Stomach-Shaped Inlet Liner in Capillary Gas Chromatographic Trace Analysis of Dioxins in Human Milk and Plasma

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