title: Toxicological screening of human plasma by on-line SPE-HPLC-DAD: identification and quantification of acidic and neutral drugs.
abstract: A multi-analyte screening method for the quantification of 50 acidic/neutral drugs in human plasma based on on-line solid-phase extraction (SPE)-HPLC with photodiode array detection (DAD) was developed, validated and applied for clinical investigation. Acetone and methanol for protein precipitation, three different SPE materials (two electro-neutral, one strong anion-exchange, one weak cation-exchange) for on-line extraction, five HPLC-columns [one C18 (GeminiNX), two phenyl-hexyl (Gemini C6 -Phenyl, Kinetex Phenyl-Hexyl) and two pentafluorophenyl (LunaPFP(2), KinetexPFP)] for analytical separation were tested. For sample pre-treatment, acetone in the ratio 1:2 (plasma:acetone) showed a better baseline and fewer matrix peaks in the chromatogram than methanol. Only the strong anion-exchanger SPE cartridge (StrataX-A, pH 6) allowed the extraction of salicylic acid. Analytical separation was carried out on a Gemini C6 -Phenyl column (150 × 4.6 mm, 3 µm) using gradient elution with acetonitrile-water 90:10 (v/v) and phosphate buffer (pH 2.3). Linear calibration curves with correlation coefficients r ≥ 0.9950/0.9910 were obtained for 46/four analytes. Additionally, this method allows the quantification of 23 analytes for therapeutic drug monitoring. Limits of quantitation ranged from 0.1 (amobarbital) to 23 mg/L (salicylic acid). Inter-/intra-day precisions of quality control samples (low/high) were better than 13% and accuracy (bias) ranged from -14 to 10%. A computer-assisted database was created for automated detection of 223 analytes of toxicological interests. Four cases of multi-drug intoxications are presented.
authors.affiliation: Berlin Institute of Technology, Department of Environmental Technology, Straße des 17. Juni 135, D-10623, Berlin, Germany.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Mut
authors.affiliation: Labor Berlin - Charité Vivantes GmbH, Department for Laboratory Medicine and Toxicology, Sylter Str. 2, D-13353, Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Grobosch
authors.affiliation: Labor Berlin - Charité Vivantes GmbH, Department for Laboratory Medicine and Toxicology, Sylter Str. 2, D-13353, Berlin, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Binscheck-Domaß
authors.affiliation: Berlin Institute of Technology, Department of Environmental Technology, Straße des 17. Juni 135, D-10623, Berlin, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Frenzel
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005260:Female; D053593:Forensic Toxicology; D006801:Humans; D057230:Limit of Detection; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D004364:Pharmaceutical Preparations / Q000097:blood* / Q000737:chemistry*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D004364:Pharmaceutical Preparations
keywords: acidic and neutral drugs; multi-analyte screening; on-line solid-phase extraction; plasma samples; systematic toxicological analysis; validation