Code of Federal Regulations (21CFR) Guidances

The detection of Δ9 -tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) in hair, for the purpose of identifying cannabis consumption, is conducted in many forensic laboratories. Since external contamination of hair with these cannabis components cannot be excluded, even after hair decontamination, only the detection of THC metabolites such as 11-nor-9-carboxy-Δ9 -tetrahydrocannabinol (THC-COOH) or 11-hydroxy-Δ9 -tetrahydrocannabinol (OH-THC), is considered to prove cannabis consumption. At present, testing for THC metabolites is not standard practice due to its analytical complexity. For these reasons, we developed a novel method for the detection of THC-COOH and OH-THC as well as THC, CBD, and CBN in one single analytical run using gas chromatography-tandem mass spectrometry (GC-MS/MS) with electron ionization. After manual hair washing and grinding, sample preparation was fully automated, by means of a robotic autosampler. The hair extraction took place by digestion with sodium hydroxide. A solid-phase extraction (SPE) was chosen for sample clean-up, using a mixed-mode anion exchange sorbent. Derivatization of all analytes was by silylation. The method has been fully validated according to guidelines of the Society of Toxicological and Forensic Chemistry (GTFCh), with a limit of detection (LOD) of 0.2pg/mg for THC-COOH and OH-THC and 2pg/mg for THC, CBD and CBN, respectively, thus fulfilling the Society of Hair Testing (SoHT) recommendations. The validated method has been successfully applied to our routine forensic case work and a summary of data from authentic hair samples is given, as well as data from proficiency tests.

The purpose of this paper was to compare the composition (weight % of total identified FA) in saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids from 3 food matrices (sunflower oil, palm oil and lard) by 2 different techniques, gas chromatography - mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). For GC-MS technique, fatty acid methyl esters (FAMEs) identification in the samples was performed by comparison of the retention times (RT) and the mass/charge (m/z) ratio characteristic of each FAME component in the reference standards used (F.A.M.E. Mix C4 - C24 and SRM®2377). FAMEs quantification from food samples was realized by applying correction factors calculated based on reference standards. NMR spectra were recorded on a Bruker Advance 400 MHz spectrometer, operating at 9.4 Tesla corresponding to the resonance frequency of 400.13 MHz for the 1H nucleus. The NMR spectra was recorded directly on the oil without any sample preparation. The difference between the mean values of the fatty acids content determined by GC-MS and NMR was not more than ± 15% for sunflower oil and lard, and ± 6% for palm oil.

We report here that easy ambient sonic spray ionization − mass spectrometry (EASI−MS) allowed direct, rapid, and comprehensive analysis of active components (e.g., terpenetrilactones and intact flavonol glycosides) in Ginkgo tablets. Unlike conventional methods that hydrolyze flavonol glycosides to flavonoids prior to analysis, EASI−MS detects intact flavonol glycosides directly from the tablets enabling differentiation of these natural glycosides from the synthetic flavonoids. Adulteration of Ginkgo tablets is therefore readily recognized in less than 10 s measurement time. Sample preparation is simple and requires only 0.5 mL of methanol and a mortar and pestle. Additionally, no reference standards are needed and a comparison is made to a certified Ginkgo tablet. To demonstrate these abilities, 22 commercial Ginkgo tablets were analyzed by EASI−MS. The data revealed large variations of ingredients and strong deviations from the specified Ginkgo extract levels. These results emphasize the importance of monitoring Ginkgo products using appropriate methodologies as suggested in our work. The technique may replace more demanding LC−MS/MS methods, which can achieve comparable results but are considerably more labor-intensive. Importantly, the presented method is cheaper, faster, and much simpler to operate than chromatography-based mass spectrometric techniques.

The microplate assay with Chinese Hamster Ovary (CHO) cells is currently used as a safety test to monitor the residual pertussis toxin (PT) amount in acellular pertussis antigens prior to vaccine formulation. The assay is based on the findings that the exposure of CHO cells to PT results in a concentration-dependent clustering response which can be used to estimate the amount of PT in a sample preparation. A major challenge with the current CHO cell assay methodology is that scoring of PT-induced clustering is dependent on subjective operator visual assessment using light microscopy. In this work, we have explored the feasibility of replacing the microscopy readout for the CHO cell assay with the xCELLigence Real-Time Cell Analysis system (ACEA BioSciences, a part of Agilent). The xCELLigence equipment is designed to monitor cell adhesion and growth. The electrical impedance generated from cell attachment and proliferation is quantified via gold electrodes at the bottom of the cell culture plate wells, which is then translated into a unitless readout called cell index. Results showed significant decrease in the cell index readouts of CHO cells exposed to PT compared to the cell index of unexposed CHO cells. Similar endpoint concentrations were obtained when the PT reference standard was titrated with either xCELLigence or microscopy. Testing genetically detoxified pertussis samples unspiked or spiked with PT further supported the sensitivity and reproducibility of the xCELLigence assay in comparison with the conventional microscopy assay. In conclusion, the xCELLigence RTCA system offers an alternative automated and higher throughput method for evaluating PT-induced clustering in CHO cells.

A simple, fast, and cost-effective sample preparation method, previously developed and validated for the analysis of organic contaminants in fish using low-pressure gas chromatography-tandem mass spectrometry (LPGC-MS/MS), was evaluated for the analysis of polybrominated diphenyl ethers (PBDEs) and dichlorodiphenyltrichloroethane (DDT) pesticides using enzyme-linked immunosorbent assay (ELISA). The sample preparation technique was based on the quick, easy, cheap, rugged, effective, and safe (QuEChERS) approach with filter-vial dispersive solid phase extraction (d-SPE). Incurred PBDEs and DDTs were analyzed in three types of fish with 3-10% lipid content: Pacific croaker, salmon, and National Institute of Standards and Technology (NIST) Standard Reference Material 1947 (Lake Michigan fish tissue). LPGC-MS/MS and ELISA results were in agreement: 108-111 and 65-82% accuracy ELISA versus LPGC-MS/MS results for PBDEs and DDTs, respectively. Similar detection limits were achieved for ELISA and LPGC-MS/MS. Matrix effects (MEs) were significant (e.g., -60%) for PBDE measurement in ELISA, but not a factor in the case of DDT pesticides. This study demonstrated that the sample preparation method can be adopted for semiquantitative screening analysis of fish samples by commercial kits for PBDEs and DDTs.

Many times when measuring the NMR spectra of certain compounds it is necessary to protect the sample from atmospheric oxygen or water. The effect of dissolved oxygen on the NMR spectrum is well known.1 It may also be necessary or desirable to obtain the NMR spectrum with the sample compound in an appropriate solvent together with a reference standard. These considerations are particularly important when obtaining reference spectra of high-purity standard-sample compounds.

Determination of chloride in milk using sequential injection automated conductimetry

A systematic strategy integrating solid-phase extraction, full scan range splitting, mass defect filter and precursor ion list for comprehensive metabolite profiling of Danqi Tongmai tablet in rats

Objective To screen the suitable sample digestion method for measuring iodine in serum by arsenic cerium catalytic spectrophotometric method, and to carry out the methodology test for the newly developed arsenic cerium catalytic spectrophotometry for determination of iodine in serum. Methods Methodology evaluation. Experimentswere on the sample on the sample digestion method of serum iodine with several common digestive agents. After digestion treatment, the concentration of iodine in serum was determined by arsenic cerium catalytic spectrophotometry. The linearity and linear range of the standard curve, detection limit, precision, recovery rate and anti-interference ability of the newlydeveloped arsenic cerium catalytic spectrophotometry were tested. Results Sample pretreatment method included in the newly developed arsenic cerium catalytic spectrophotometry was selected as follows: perchloric acid-sodium chlorate solution was used as the digestive agent to digest 120 min at 130℃. The calibration relation of C=a+ blgA(C: iodine concentration, A: measuring absorbance) of the newly developed method existed when arsenic ceriumcatalytic reaction was kept at a certain stable temperature range from 13℃ to 30℃ and in certain stable reacting time. The linear range of the calibration curvewas 0 -300 μg/Land the linear correlative coefficient was -0.9996--0.9999. The intra assay coefficients of variation(CVs ) were 0.70%, 0.70% and 0.74% (n=6), and the inter assay CVs were 0.57%, 0.51% and 0.57% (n=6) for 3 serum samples. The average recovery was 97.9% with a range from 92.3% to 105.8% for 3 serum samples. Conclusions The newly developed arsenic cerium catalytic spectrophotometry has good precision and accuracy. The sample digestion agent is easy to be prepared and reserved, and the instrument is simple and easy to be operated. The method can be widely used as a reliable technique for measuring iodine in serum.(Chin J Lab Med, 2017, 40: 119-125) Key words: Iodine; Serum; Reference standards; Spectrophotometry; Arsenicals; Cerium

Health wines are alcoholic beverages produced by infusing traditional liquors or rice wines with natural, medicinal, and food-safe ingredients. However, to accelerate efficacy, some manufacturers illegally adulterate health wines with phosphodiesterase type 5 (PDE-5) inhibitors, which may cause severe adverse effects. This study developed a method based on ultra-high-performance liquid chromatography–time-of-flight mass spectrometry (UPLC–TOF/MS) for the rapid screening and identification of 68 PDE-5 inhibitors illegally added to health wines. After optimizing the sample preparation procedure, chromatographic conditions, mass spectrometric parameters, and primary and secondary mass spectra of the 68 PDE-5 inhibitors were acquired as reference standards. Retention times and mass spectral data were imported into the Personal Compound Database and Library, establishing a high-resolution screening database with matched drug names, molecular formulas, and accurate molecular weights. A quantitative method was validated using 11 commonly adulterated compounds, including sildenafil. The response was highly linear (r ≥ 0.9988; 0.8–400 μg/L) with low detection limits (0.2–1.0 μg/L). The average spiked recoveries were 71.2–104.1%, with relative standard deviations of ≤10.1%. Among 59 commercial health wine samples, three batches tested positive for PDE-5 inhibitors (detection rate: 5.1%). The proposed method can assist market surveillance even when reference standards are unavailable for all compounds.

A review of nine years of NPS synthesis research projects supported by EUROSTARS

A variety of LSD analogs have emerged in recent years with dual purposes of avoiding prosecution from possession while providing new options for those willing to experiment with hallucinogenic drugs. In this study, a previously published automated sample preparation method for LSD and its primary metabolite (OH-LSD) was utilized to extract LSD, OH-LSD, and nine LSD analogs from urine. The liquid chromatography tandem mass spectrometry (LC-MS/MS) method was modified from the previously published LC conditions to utilize a different analytical column and gradient elution program. Mobile phases of 10 mM ammonium formate with 0.1% formic acid in deionized water (mobile phase A) and 0.1% formic acid in methanol (mobile phase B) were employed. The method was validated to ANSI/ASB Standard 036 with a 0.1 ng/mL limit of detection for all analytes and was utilized for the analysis of 325 urine specimens. Although no LSD analogs were observed in the samples analyzed, this validated method was demonstrated to be suitable for the analysis of these compounds in laboratories seeking to expand their testing scope. Automated sample preparation allows for the efficient analysis of these analytically challenging compounds with minimal manual handling. Additionally, there was no increased analytical time burden when the LC column and gradient were modified to target nine additional analytes. Detection may improve as new reference standards are developed to allow laboratories to focus on the metabolic products of these analogs. For now, this validated procedure can assist with the routine analysis and surveillance of these emerging substances.

Quantitative estimation of α-PVP metabolites in urine by GC-APCI-QTOFMS with nitrogen chemiluminescence detection based on parent drug calibration

A sample preparation method is described which permits fast and accurate wavelength‐dispersive, x‐ray fluorescence analysis of ten major oxides in carbonate rocks. The sample is first ground into a fine powder, then calcined, its loss‐on‐ignition (LOI) is determined and finally it is fused into a glass disc with lithium tetraborate at 1100°C using a 1:10 sample‐to‐flux ratio. Geological reference standards and synthetic standards are used for calibration. Matrix effects are corrected empirically using Lachance‐Traill correction algorithms. The accuracy and precision of the method were assessed by the analysis of several NBS carbonate reference standards.

Extra virgin olive oils (EVOOs) containing more than 5 mg/20 g tyrosol, hydroxytyrosol, and their secoiridoids can be recognized by health claims related to the protection of blood lipids from oxidative stress. Therefore, a reliable, accurate, and standardized analytical procedure is needed to determine these markers of EVOO quality. In order to overcome the limitations of current methods, a detailed investigation of sample preparation and chromatographic conditions was performed by UHPLC-UV-HRMS. The use of a C18 fused-core column and nonacidified gradient elution provided single, sharp peaks for oleocanthal and oleacein, allowing their reliable quantitation in UV profiles. Positive- and negative-UHPLC-HRMS/MS characterization of methanolic extracts revealed the presence of dimethyl acetal, methyl hemiacetal, and monohydrate derivatives of all secoiridoids. These artifacts were formed in aqueous methanol, which is usually employed to extract and analyze EVOO phenols, making the HPLC profiles more complex and the measurements less accurate and reproducible. Acetonitrile proved to be a suitable solvent to avoid the formation of secoiridoid dimethyl acetals and methyl hemiacetals and to efficiently extract EVOO bioactive phenols. Finally, the phenolic contents of Italian EVOO samples were determined by UHPLC-UV analysis of acetonitrile extracts before (direct method) and after acid hydrolysis (indirect method). The results indicated that the use of tyrosol and hydroxytyrosol as reference standards allowed more accurate quantitative data to be obtained. Direct and indirect methods provided comparable levels of EVOO phenols, highlighting the usefulness of acid hydrolysis in routine analyses. The improved procedure defines the most reliable conditions to provide an analytical method with suitable accuracy and repeatability in the analysis of healthy and functional EVOO phenols.