Harald Schütz

Immunoassays for drug screening in urine

Immunoassays are presently used worldwide for the rapid screening of drugs. Despite the fact that they are a highly valuable tool for the testing of legal and illicit drugs, there is a real risk of false-positive and false-negative findings and many pitfalls must be taken into account when these tests are used in an uncritical manner and without valid confirmation procedures. In a long-standing successful cooperation with a large psychiatric hospital, we checked doubtful and nonplausible immunochemical findings in urine with gas chromatography-mass spectrometry (GC-MS) confirmation methods. The reported case histories demonstrate typical pitfalls, for example, influence of changing nutritional habits, use of sweeteners (cyclamate), uncritical creatinine correction, impaired elimination, or cross-reactivities of simultaneous therapeutic medication. In accordance with national and international associations, immunoassays are recommended as a useful tool for screening. However, confirmation analysis with conclusive methods (GC-MS or liquid chromatography-MS) is unavoidable for valid substance identification, discrimination between active and inactive metabolites, detection of congeners, and accurate determination of concentrations in body fluids.

Multiple homicides as a result of chloroform poisoning: case report and experimental study.

Two cases (involving five murder victims) of multiple homicide by inhalational chloroform intoxication are reported. In the discussion of the findings the valence of toxicological analyses is underlined with regard to the possibility of forcible external suffocation due to occlusion of the respiratory orifices by means of a chloroform-soaked soft covering. In addition storage experiments were performed at +4, +20 and -20 degrees C with cadaver blood mixed with chloroform. The optimal solution for avoiding volatile losses was stored in glass tubes with ground glass stoppers. In cases of unclear death in which involvement of volatile substances is suspected it is, therefore, advisable to preserve an additional blood sample at -20 degrees C in glass tubes that are only opened for the analysis of volatile substances.

Detection of morphine and monoacetylmorphine (MAM) in human hair

SummaryThe detection of opiates and their metabolites in human hair has obtained an increasing importance in forensic toxicology, but many compounds [e.g. the heroin marker 6-monoacetylmorphine (MAM)] are regularly destroyed by the use of invasive extraction and hydrolysis procedures. This paper describes a method for the analysis of such sensible structures by means of guanidine/mercaptoethanol treatment, followed by specific solid phase extraction. The detection limit is better than 1 μg/g hair.

Modern screening strategies in analytical toxicology with special regard to new benzodiazepines

SummaryScreening procedures for the detection of toxicologically relevant substances have become of ever-increasing importance due to the rapid development of new substances. Identification methods must be simple, sensitive, and practicable. This article describes standardized chromatographical (corrected Rfcvalues, retention indices) and immunological methods (enzyme-multiplied immunoassay technique, fluorescent polarization immunoassay) with special regard to the screening of some newer benzodiazepines, a class of substances that is still expanding. Some of these new compounds may be integrated in well-known screening procedures (via aminobenzophenones and detection by the Bratton-Marshall reagent); others require special concepts for detection. The problems are indicated and discussed, including the use of high-pressure-liquid chromatography and mass spectrometry; recommendations are given.ZusammenfassungDie ständig zunehmende Zahl toxikologisch relevanter Fremdstoffe erfordert leicht praktikable aber dennoch empfindliche und aussagekräftige Screeningverfahren, um im Rahmen der General-Unknown-Analyse möglichst rash gezielte Hinweise auf eine bestimmte Substanz oder eine ganze Wirkstoffgruppe zu erhalten.Die Senatskommission für Klinisch-toxikologische Analytik der Deutschen Forschungsgemeinschaft hat in Zusammenarbeit mit der TIAFT (The International Association of Forensic Toxicologists) bereits vor längerer Zeit die Aufgabe übernommen, solche Screeningkonzepte zu überprüfen, weiter zu entwickeln und verläßliches Datenmaterial zur Verfügung zu stellen.In der vorliegenden Arbeit werden zunächst die Konzepte des korrigierten Rfc-Wertes in der Dünnschichtchromatographie, des Retentionsindex in der Gaschromatographie sowie wichtiger immunologischer Verfahren zum Screening beschrieben, um die prinzipielle Arbeitsweise der verschiedenen Methoden zu veranschaulichen. Neben diesen methodischen werden jedoch auch stoffliche Aspekte berücksichtigt: Für Neuentwicklungen auf dem Gebiet der Benzodiazepine, einer immer noch rasch expandierenden Stoffklasse, wurde umfangreiches Datenmaterial erarbeitet und zusammengestellt. Einige dieser Benzodiazepine lassen sich in bestehende Screeningprogramme (z.B. über Benzophenone und Bratton-Marshall-Detektion) integrieren, andere können nur über die Rfc-Werte erfaßt werden. Schwierigkeiten und Vorschläge für ihre Beseitigung werden auch im Zusammenhang mit den immunologischen Verfahren aufgezeigt bzw. diskutiert. Weiterhin werden einige Aspekte der Hochdruckflüssigkeitschromatographie (HPLC) und der Massenspektrometrie (MS) im Zusammenhang mit Screeningfragen angesprochen. Der Beitrag schließt mit Empfehlungen zum Einsatz der einzelnen Methoden unter besonderer Berücksichtigung des Benzodiazepin-Screenings.

TLC-screening of important pharmaceutical substances using fluorescence detection

SummaryObservation of fluorescence reactions on TLC plates is a valuable additional tool within the scope of screening procedures for many toxicologically relevant substances commonly encountered in clinical- and forensic-toxicological analysis. The reactions are based on native fluorescence without any treatment and on reactions obtained with an approved derivatization procedure. Due to the enormous sensitivity of the fluorescence detection, the method is also applicable to very low concentrations and small amounts of biological materials. The procedures described in this article have proven their high pragmatic usefulness in many practical cases.

A TLC screening program for 170 commonly used pesticides using the corrected Rf value (R f c value)

SummaryThis article reports TLC data (corrected Rf values; Rfc values) of 170 commonly used pesticides which are regularly encountered in toxicological analysis. Silica gel was used as the stationary phase and three binary systems were chosen as solvents.ZusammenfassungEs werden DC-Daten (korrigierte Rf-Werte; Rfc-Werte) für 170 gebräuchliche Pestizide mitgeteilt, die häufig im Rahmen toxikologischer Analysen anfallen. Als stationäre Phase wurde Silicagel gewählt; als Fließmittel dienen drei binäre Systeme.

Infanticide and Neonaticide

Infanticide and child homicide are seen in many forms and under widely varying circumstances:

Zur Analytik von Flunitrazepam (Rohypnol), einem neuen Benzodiazepinderivat, unter besonderer Berücksichtigung der Metaboliten

SummaryThe article describes analytical data (TLC, GLC, IR, UV and MS) of flunitrazepam, 7-amino-flunitrazepam, desmethylflunitrazepam, 3-hydroxyflunitrazepam, 7-amino-desmethyl-flunitrazepam and many other benzodiazepine-derivatives, especially aminobenzophenones. Also extraction from biological specimen is reported.ZusammenfassungIn der Arbeit werden analytische Daten (DC, GLC, IR, UV, MS) von Flunitrazepam, 7-Aminoflunitrazepam, Nor-Flunitrazepam, 3-Hydroxyflunitrazepam, 7-Amino-nor-flunitrazepam und zahlreichen anderen Benzodiazepinen und Aminobenzophenonen mitgeteilt. Weiterhin wird über die Aufarbeitung biologischen Untersuchungsmaterials berichtet.

Child Sexual Abuse

In routine practice, underage victims of sexual abuse rarely usually undergo gynecological examination by a forensic expert, but rather by a gynecologist. However, forensic medical experts are called upon to gather extragenital findings and to interpret findings in the context of the reported patient history and overall findings. The absence of evidence of abuse is not evidence of the absence of abuse. At the same time, self-inflicted injury sometimes needs to be considered in the case of older children.

Pointed, Sharp, and Semi-sharp Force Trauma

Cutting implements, particularly knives, cause injuries classified as sharp force trauma, i.e., stab and incised (cut) wounds. Semi-sharp trauma comprises chop wounds, e.g., from saws, and bites wounds. Pointed force trauma includes injuries caused by firearms and pointed instruments, comparable to puncture wounds.