Drug Testing and Analysis

A fast GC-MS method for screening NPS is described and applied to 35 legal high products obtained from the Internet and head shops.

The products do not always contain their stated ingredients and, of the group of products purchased as 5-IAI, not one contained this NPS.

The substituted cathinone, mephedrone, is generally consumed orally or by snorting but reports indicate that it is also ingested by vaporization/inhalation (‘smoking’). This study examines the pyrolysis products produced by heating mephedrone under using simulated ‘meth pipe’ conditions. A variety of compounds are produced and there is evidence of thermal rearrangement, methylation, condensation/dimerization, halogenation and oxidative degradation.

Methods are presented for the sensitive detection of fluticasone propionate in horse plasma and a carboxylic acid metabolite in horse urine. Following an inhaled administration of FP, FP was detected in plasma for a minimum of 72 hours and FP-17βCOOH was detected in urine for approximately 18 hours. We believe this to be the first reported detection of FP-COOH in the horse.

Genetic algorithm and partial least square (GA-PLS) and Levenberg- Marquardt artificial neural network (L-M ANN) techniques were used to investigate the correlation between retention time and descriptors for drug metabolites which obtained by twodimensional liquid chromatography. The applied internal (leave-group-out cross validation (LGO-CV)) and external (test set) validation methods were used for the predictive power of four models. Both methods resulted in accurate prediction whereas more accurate results were obtained by L-M ANN model.

A QSRR study based on an ANN was carried out for the prediction of the UPLC-TOF-MS retention time (RT) of a set of 52 pharmaceuticals and drugs of abuse in hair. The results indicated that L-M ANN could be used as a powerful modeling tool for this research. A plot of predicted RT versus experimental RT values by L-M ANN for training set is shown in below figure.

Bar plots for comparison of the RMSEP values obtained by application of the four adopted chemometric methods for the analysis of the independent test set Performance of PLSR is enhanced in the presented work by three multivariate modelling approaches including weighted regression PLS (Weighted-PLSR), genetic algorithm PLSR (GA-PLSR) and wavelet transform PLSR (WT-PLSR). The proposed models were investigated for their application to the stability indicating analysis of mixtures of mebeverine hydrochloride (meb) and sulpiride (sul) in presence of their reported impurities and degradation products. The work aims to compare these different chemometric methods, showing the underlying algorithm for each and making a comparison of analysis results.

A sensitive ELISA has been developed and validated for determination of rosuvastatin in plasma samples at pictogram level based on a competitive binding immuno-reaction.

A novel method for determination of andrographolide using flow-injection chemiluminescence (FI-CL) analysis is described in this paper. The chemiluminescence intensity of the solution was enhanced proportionally while the concentration of andrographolide increased. Under the selected experimental conditions, the calibration curve of andrographolide was linear within the range of 0.2 to 35.0 µg mL⁻¹ with a linear equation of ΔI = 23.391x (µg mL⁻¹) + 34.191, R² = 0.9965.

• Application of integration of the advantages of MBs and AuNPs in small molecule.
• The LOD of the methods in milk for CAP were far lower than the MRPLs.
• Two different extract methods for CAP have their own advantages.

An orthogonal-signal correction-partial least squares method was developed for the simultaneous spectrophotometric determination of orotic acid (OA), creatinine (CRE), and uric acid (UA) in spiked real samples.

Calibration matrices contained 1.74–47.00 of OA, 1.13–33.95 of CRE, and 1.68–28.58 of UA in mg/ml. The number of principal component for OA, CRE, and UA with OSC were 3, 4, and 4. The proposed method was applied for the simultaneous determination of OA, CRE, and UA in real samples.

MALDI-FTMS as a useful procedure for drug testing in single hairs demonstrated for cocaine and THC in an authentic case.

Optimization and validation of preliminary immunoassay tests with respect to the German per-se limits for driving under the influence of drugs (serum) and lowered cut-offs in cases of driving licence re-granting (urine).

During the FIFA U-17 World Cup in 2011, clenbuterol was detected in 109 out of 208 doping control samples. The findings were attributed to food contamination issues as corroborated by food analyses indicating the illicit use of clenbuterol as growth promoter and, as a consequence, the inadvertent ingestion of the drug by the athletes.