Determination of disperse dyes on polyester fibers by UHPLC–Orbitrap MS

The determination of fiber dyes is important in forensic investigations. Although a variety of fiber dyes detection methods have been established, the sensitive and accurate determination of trace fiber dyes remains a challenge due to the possible interferences caused by complex environmental matrix and various fiber additives. Orbitrap mass spectrometry (Orbitrap MS) is a type of high-resolution mass spectrometry with high qualitative accuracy and detection sensitivity which highly meet the identification requirements of fiber dyes in real cases. However, the application of Orbitrap MS in fiber dye analysis is limited. In this regard, this study used polyester fiber, which is the most commonly-found fiber in forensic cases, as a model and established a UHPLC–Orbitrap MS method to analyze disperse dyes on polyester fibers. Using the optimized UHPLC–Orbitrap MS method, nine disperse dyes were accurately identified and well separated, and the limits of detection ranged between 0.1 ng/mL and 5.0 ng/mL. The developed method was applied to analyze actual fiber samples, and dyes from single fibers of 1 mm in length could be accurately detected. The established method is sensitive, accurate, and demonstrates good application prospects.     

涤纶纤维上分散染料的液-质分析

目的建立液-质联用技术对涤纶纤维上分散染料进行分析的方法。方法以N,N-二甲基甲酰胺为提取剂,在负离子模式下对12个黄色涤纶纤维上分散染料进行分析。结果12种分散染料在负离子模式质谱检测条件下均得到了有效的分析。根据一级负离子模式下总离子流图中准分子离子峰质荷比的不同,可将其中8种样品一一鉴别开。在此基础上,从染料离子化产物中选取响应信号较强的准分子离子为母离子,再对母离子进行二级质谱全扫描,依据二级质谱图中特征碎片峰的数目、质荷比的异同可对纤维上染料进一步进行鉴别。结论液-质联用法是检验有色纤维上染料的一种科学、有效的方法。     

Forensic identification of dyes extracted from textile fibers by liquid chromatography mass spectrometry (LC-MS)

LC-MS is used for the identification of dyes extracted from textile fibers and the utility of the method for forensic trace analysis is demonstrated. The technique is shown to provide a high degree of chemical structural information, making dye identification highly specific in comparison to optical and/or chromatographic methods of dye analysis. A UV-visible absorbance detector, placed in series before the MS detector, facilitates monitoring the elution of dyes in the presence of other non-dye components extracted from colored textile fibers. In this way, dye identification becomes practical, even when a dye standard is not available for comparison. A set of 22 reference dyestuffs and 10 dyes extracted from textile fibers were analyzed to demonstrate the utility of the method. Six of the extracted dyes corresponded to dyes also contained in the set of 22 reference dyestuffs. Reference dyestuffs were not available for four of the extracted dyes. Triethylamine (TEA) was shown to increase the electrospray ionization-mass spectrometry (ESI-MS) response of dyes containing multiple sulfonated groups.     

Characterization and Differentiation of Geometric Isomers of 3‐methylfentanyl Analogs by Gas Chromatography/Mass Spectrometry,Liquid Chromatography/Mass Spectrometry,and Nuclear Magnetic Resonance Spectroscopy

The cis and trans isomers of 3‐methylfentanyl and its three analogs were chemically synthesized, and these compounds were characterized and differentiated by gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), and nuclear magnetic resonance (NMR) spectroscopy. The cis and trans isomers of the 3‐methylfentanyl analogs were completely separated by GC/MS. Although the high temperature of the GC injection port caused thermal degradation of β‐hydroxy‐3‐methylfentanyl, the degradation was completely suppressed by trimethylsilyl derivatization. The isomers were also well separated by LC/MS on an octadecylsilyl column with 10 mM ammonium acetate and methanol as the mobile phase. The proton NMR signals were split when the hydrochloride salts of the 3‐methylfentanyl analogs were dissolved in deuterated chloroform because stereoisomers were formed by the coordination of the hydrochloride proton to the nitrogen of the piperidine ring of the 3‐methylfentanyl analogs.     

A Polydrug Intoxication Involving Methoxetamine in a Drugs and Driving Case

Methoxetamine ((RS)2‐(3‐methoxyphenyl)‐2‐(ethylamino)cyclohexanone)) is becoming a drug of interest among practitioners of forensic toxicology. In this case report, we describe the case background, standard field sobriety tests, sampling, and analysis of this drug in a whole blood sample as well as screening methods and analysis from a driver operating under the influence of intoxicating substances. Methoxetamine was isolated from the blood sample using mixed mode solid phase extraction. After elution and evaporation, the residue was dissolved in mobile phase (consisting of acetonitrile and aqueous formic acid) for analysis by liquid chromatography–tandem mass spectrometry (LC–MS/MS) and gas chromatography–mass spectrometry (GC–MS). The case sample was found to contain clonazepam, 7‐aminoclonazepam, carboxy‐THC, Ddphenhydramine, and MDMA. The case sample was found to contain 10 ng/mL of the drug (methoxetamine) in whole blood. The results of this drug analysis and previous analyses are discussed in terms of this driver operating under the influence of drugs.     

液相色谱-串联质谱法检测血液中的美西律

目的建立测定血液中美西律(mexiletine)的液相色谱-串联质谱联用法(LC-MS/MS)。方法采用简便的乙腈蛋白沉淀法对血液进行预处理,应用Allure PFP Propyl液相柱分离,用电喷雾正离子模式离子化,多反应监测模式对美西律进行分析。结果美西律与内标纳洛酮分离良好,在0.02～10.00μg/mL内线性关系良好,相关系数为0.9999,回归方程为y=0.0283x-0.0151,日内与日间精密度的RSD均小于15%,最低检测限为0.01μg/mL。结论建立的LC-MS/MS方法简单、灵敏、可靠,可同时适用于美西律临床药物监测和法医毒物分析的需要。     

Application of Raman Spectroscopy and Surface‐Enhanced Raman Scattering to the Analysis of Synthetic Dyes Found in Ballpoint Pen Inks*

Abstract: The applicability of Raman spectroscopy and surface‐enhanced Raman scattering (SERS) to the analysis of synthetic dyes commonly found in ballpoint inks was investigated in a comparative study. Spectra of 10 dyes were obtained using a dispersive system (633 nm, 785 nm lasers) and a Fourier transform system (1064 nm laser) under different analytical conditions (e.g., powdered pigments, solutions, thin layer chromatography [TLC] spots). While high fluorescence background and poor spectral quality often characterized the normal Raman spectra of the dyes studied, SERS was found to be generally helpful. Additionally, dye standards and a single ballpoint ink were developed on a TLC plate following a typical ink analysis procedure. SERS spectra were successfully collected directly from the TLC plate, thus demonstrating a possible forensic application for the technique.     

Morbidity Involving the Hallucinogenic Designer Amines MDA and 2C‐I*

Abstract: A case is presented of a 39‐year‐old woman who suffered severe debilitation because of a hemorrhagic stroke in the context of substance abuse. The patient presented to the emergency room with rapidly diminishing mental status, hypertension, and vasoconstriction; her friends provided a history of ingestion of cocaine, 3,4‐methylenedioxymethamphetamine (MDMA), and 2C‐I, a novel designer amine. A multi‐targeted LC‐MS/MS method for sympathomimetic amines and related drugs in urine detected and quantified 2C‐I and MDA, while ruling out MDMA. The cause of the stroke was determined to be an underlying cerebrovascular abnormality called Moyamoya, secondary to substance abuse. In clinical laboratories, gas chromatography–mass spectrometry or liquid chromatography–tandem mass spectrometry (LC‐MS/MS) confirmation of a positive amphetamine immunoassay is usually directed only towards amphetamine, methamphetamine, MDMA and MDA. This report demonstrates the utility of testing for a wider menu of compounds using LC‐MS/MS in order to better characterize the prevalence and toxicities of novel amines such as 2C‐I.     

Analysis of biofluids for flunitrazepam and metabolites by electrospray liquid chromatography/mass spectrometry

A rapid and sensitive liquid chromatography/electrospray ionization mass spectrometry (LC/MS) procedure has been developed for the analysis of biofluids containing flunitrazepam and its metabolites. Specimens were spiked with deuterated analogs of the analytes. Urine specimens were enzymatically hydrolyzed and blood specimens were untreated. Extractions were carried out using CleanScreen DAU SPE cartridges. The drugs were separated on a C18 column using a methanol-water-ammonium hydroxide (60:40: 0.03 v/v) mobile phase. After determination of base peaks using full scan mass spectrometry, the mass spectrometry method was optimized to operate in selected-ion monitoring (SIM) mode for the base peak of each analyte. Positive findings were confirmed by LC/MS/MS using the same mobile phase and column. This analytical procedure allows for the detection of low levels of flunitrazepam and metabolites in biofluids. It is useful for ascertaining the role of flunitrazepam in cases of drug-facilitated sexual assault.     

Ballpoint pen inks: characterization by positive and negative ion-electrospray ionization mass spectrometry for the forensic examination of writing inks

A method based on profiling of dye components by electrospray ionization mass spectrometry (ESI/MS) is described for the characterization of ballpoint pen inks. The method involves benzyl alcohol (30 microL) extraction of ink from paper. The extracts of ink lines 1 and 5 mm in length are used for direct ESI/MS analysis in positive and negative modes, respectively. The instrumental analysis takes 3 min. Basic and acid dyes in the inks are detected in the positive and negative modes, respectively, with each dye yielding one or two characteristic ion peaks. The mass spectrum, which is mainly a compositional signature of the dyes in the ink, was not affected by the type of paper from which the ink was extracted, or by natural ageing of the ink on document in the absence of light. However, exposure to fluorescent illumination caused dealkylation of polyalkylated basic dyes and resulted in changes in the homologous distribution of the dyes. In this study, a total of 44 blue inks, 23 black inks, and 10 red inks have been analyzed, and the mass spectra were used to establish a searchable library. ESI/MS analysis provides a simple and fast way to compare ink specimens and in combination with on-line library search permits rapid screening of inks for forensic document investigations.     

The Characterization of 3,4-Dimethylmethcathinone (3,4-DMMC)

Analogs and derivatives of traditional illicit drugs are ever increasing in variety and creativity. Staying abreast of the new developments is a constant challenge for every forensic laboratory. Recently, a seizure from Australian Customs Service presented our laboratory with the designer cathinone 3,4-dimethylmethcathinone (3,4-DMMC). Gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, and ultraviolet (UV) spectrophotometry were employed to analyze the spectroscopic characteristics of this cathinone. As an analog, 3,4-DMMC exhibits similar if not identical IR and UV profiles to mephedrone (4-MMC) and methcathinone; however, the retention time from GC is unique as expected, and the electron impact fragmentation pattern is consistent with the fragmentation pattern of other cathinones. The chemical shifts of the carbons and hydrogens were assigned by both one- and two-dimensional NMR techniques, while the molecular weight was confirmed by LC/MS.     

Quantitative Analysis of Gamma‐Hydroxybutyrate at Endogenous Concentrations in Hair using Liquid Chromatography Tandem Mass Spectrometry

Abstract: A method capable of quantifying endogenous concentrations of gamma‐hydroxybutyrate (GHB) in human head hair was developed and validated using liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS). Hair was digested under alkaline conditions, and GHB was isolated using liquid–liquid extraction. LC/MS/MS was performed using atmospheric pressure chemical ionization in the negative mode, multiple reaction monitoring, and deuterated internal standard (GHB‐D₆). Linearity was observed between 0.1 and 100 ng/mg GHB (R² = 1.000). The limits of detection and quantitation in human hair were 0.2 and 0.4 ng/mg, respectively. Accuracy at 2 ng/mg and 10 ng/mg was determined to be 97% and 94%, and intra‐assay CVs at these concentrations were 5.2% and 7.4% (n = 4). Beta‐hydroxybutyrate (BHB), alpha‐hydroxybutyrate, gamma‐butyrolactone, and 1,4‐butanediol did not produce an interference, and there was negligible ion suppression or enhancement from the matrix.     

Simultaneous identification/determination system for phentolamine and sildenafil as adulterants in soft drinks advertising roborant nutrition

An easily available, simultaneous identification/determination procedure for phentolamine (PHE) and sildenafil (SIL) in adulterated dietary supplements was established by using a combination of three different analytical methods; thin-layer chromatography (TLC), liquid chromatography–mass spectrometry (LC/MS) and a high-performance liquid chromatography (HPLC)/photo-diode-array. The sample solution for TLC was applied to silica gel 60 F₂₅₄ plates with chloroform/ammonia solution (28)/methanol (70:5:3, lower layer) and chloroform/diethylamine/methanol (15:3:2) as the developing solvent. Spots were located under UV radiation at 254 nm. Mass spectra of PHE and SIL by LC/MS were investigated with electrospray ionization (ESI) interface, under both positive and negative ion mode. The HPLC analysis was performed on a column of Wakosil 5C18 (4.6 mm×150 mm, 5 μm) with water/methanol/acetonitrile/triethylamine (580:250:170:1) adjusted with phosphoric acid to pH 3.0 as the mobile phase, and the effluent was monitored with a photo-diode-array detector. Quantitative HPLC analysis of PHE and SIL were detected at 280 nm. When this procedure was applied to commercial soft drinks, PHE and SIL were identified and determined at a concentration of 17 mg PHE and 44 mg SIL per bottle, respectively. The procedure described here is available for the screening of PHE and SIL in adulterated supplements.     

Evaluation of a Headspace Solid‐Phase Microextraction Method for the Analysis of Ignitable Liquids in Fire Debris

The chemical analysis of fire debris represents a crucial part in fire investigations to determine the cause of a fire. A headspace solid‐phase microextraction (HS‐SPME) procedure for the detection of ignitable liquids in fire debris using a fiber coated with a mixture of three different sorbent materials (Divinylbenzene/Carboxen/Polydimethylsiloxane, DVB/CAR/PDMS) is described. Gasoline and diesel fuel were spiked upon a preburnt matrix (wood charcoal), extracted and concentrated with HS‐SPME and then analyzed with gas chromatography/mass spectrometry (GC/MS). The experimental conditions—extraction temperature, incubation and exposure time—were optimized. To assess the applicability of the method, fire debris samples were prepared in the smoke density chamber (SDC) and a controlled‐atmosphere cone calorimeter. The developed methods were successfully applied to burnt particleboard and carpet samples. The results demonstrate that the procedure that has been developed here is suitable for detecting these ignitable liquids in highly burnt debris.     

The detection of multiply charged dyes using matrix-assisted laser desorption/ionization mass spectrometry for the forensic examination of pen ink dyes directly from paper

Abstract:  Laser desorption mass spectrometry (LDMS) is emerging as a technique for questioned document examination. Its use is limited to detecting ink dyes that are neutral or singly charged. Several inks contain dyes that are multiply charged and LDMS cannot be employed for their identification. We have successfully detected >20 polyionic dyes that can be used in the manufacture of inks using matrix-assisted laser desorption/ionization (MALDI) MS, directly from paper, with the matrix, 2-(4-hydroxyphenylazo)benzoic acid (HABA), and the additive, diammonium hydrogen citrate (DAHC). For example, Acid Violet 49, a charged dye containing one positively-charged site and two negatively charged sulfonate groups, cannot be detected by LDMS, but forms intact, singly charged ions in the MALDI MS experiment. The method described is also useful for identifying multiply charged dye mixtures that are used in modern pen inks.     

The importance of thin layer chromatography and UV microspectrophotometry in the analysis of reactive dyes released from wool and cotton fibers

Samples of reactively-dyed wool and cotton were obtained from a range of dye manufacturers, dye distributors and the Forensic Science Service (FSS) Fibre Data Collection. The wool fibers were red in color and had previously been compared using comparison microscopy (CM), visible range microspectrophotometry (VS) and thin layer chromatography (TLC). The cotton fibers were blue and black in color and had not been previously compared. Red, blue and black fibers were chosen because they are often encountered in casework. The usage of reactive dyes to color fibers has increased over the last 10-15 years and these are often seen in casework. Before techniques were available that allowed reactively-dyed fibers to be compared using TLC only CM and microspectrophotometry were routinely carried out. Many laboratories, who had a microspectrophotometer, only had a visible range instrument. It was therefore important to see which techniques provide additional information, that gives greater individuality to fibers, to that obtained from CM. The color was released from the wool and cotton fibres using alkaline hydrolysis and a cellulase enzyme respectively. Many of the red wool samples were differentiated from each other using CM. More differentiation was found using VS and even more when ultraviolet range microspectrophotometry (UV) or TLC was used. Two samples could only be differentiated using TLC because CM, VS and UV failed to separate them. The black cotton samples were predominately differentiated using CM but VS allowed for further differentiation. With the samples used in this project UV and TLC failed to separate the samples further. The blue cotton samples benefited from the use of CM, VS and either UV or TLC to reduce the number of matching pairs. All techniques aided differentiation although with this set TLC and UV proved to be complementary techniques. Results demonstrate that TLC and UV both yield important information over and above that obtained from CM and VS. Although in some parts of the project TLC and UV are complementary if the concentration of the dye in the fiber is not sufficient for TLC or the scientist doesn't wish to 'destroy' the fiber UV would be of more use than TLC.     

The direct detection and identification of staining dyes from security inks in the presence of other colorants, on currency and fabrics, by laser desorption mass spectrometry

Laser desorption mass spectrometry (LDMS) is useful for the direct desorption and MS analysis of dyes off materials such as paper. Here it is shown that staining dyes, produced by currency degradation devices, such as those used by financial institutions or armored transport companies, can be detected by LDMS. These staining dye packs are commonly used in bank security programs to deter theft or unauthorized removal of currency from teller stations or from ATM cash cassettes. Working automatically, these technologies release a security dye to degrade the surface of the notes and possibly mark the assailant involved in the attack. These dyes can be characterized and identified directly from paper currency, and from fabrics, and uniquely identified in the presence of other dyes that are used in the printing and dying of such materials, by LDMS. In these experiments, no extraction step is required. A pulsed UV laser directly irradiates a paper or fabric sample--colorants are desorbed, ionized and detected using time-of-flight MS. Results shown here suggest that dyes such as Basic Red 1:1 and Basic Violet 11:1 are used in such devices.     

Use of Xylazine in Drug‐Facilitated Crimes

Human xylazine poisoning is uncommon. This report describes the use of xylazine for intentional poisoning with criminal intent. Two incidents occurred within 3 weeks: the first involved one victim, and the second involved two victims. The clinical presentations were brief coma, bradycardia, hypotension, and hyperglycemia. The victims recalled having been given a drink from a stranger in a hospital waiting room before loss of consciousness. In the first case, general drug screening by gas chromatography/mass spectrometry (MS) revealed xylazine in the gastric contents, but liquid chromatography–tandem MS (LC‐MS/MS) of serum did not. In the second incident, LC‐MS/MS screening of both victims’ urine and serum samples revealed an unknown peak in the total ion chromatograms, which a molecular mass database identified as morantel or xylazine. The latter was confirmed by comparison with a xylazine standard. Based on this report, we suggest that xylazine should be classified as a controlled drug.     

A case of fatal intoxication from metformin

A case of fatal intoxication from metformin is presented. The decedent was an obese 58-year-old-woman with type II diabetes, in whom severe lactic acidosis secondary to metformin accumulation was precipitated by acute renal failure. She had been on metformin 500 mg twice a day. Postmortem blood was deproteinated with acetonitrile, washed with dichloromethane, and the resulting supernatant injected into high-performance liquid chromatography system. Separation was performed on a analytical 125 x 4 mm i.d. RP-8 column. The wavelength was set at 235 nm. The mobile phase was acetonitrile (40%), sodium lauryl sulfate, and sodium dihydrogen phosphate adjusted to pH 5.1 (60%) at a flow rate of 1.0 mL/min. The concentration of metformin in postmortem blood was 77.3 microg/mL. The qualitative result was also confirmed by LC/APCI/MS/MS analysis.     

Detection of Cutting Agents in Drug‐Positive Seized Exhibits within the United States

The following report summarizes a study performed on seized drug exhibits collected in two U.S. states to evaluate the presence and identification of cutting agents. Aliquots of seized drug materials from Kentucky (n = 200) and Vermont (n = 315) were prepared using a dilute‐and‐shoot procedure. Initial analysis was performed using gas chromatography–mass spectrometry (GC‐MS) followed by analysis using liquid chromatography quadrupole time‐of‐flight mass spectrometry (LC‐QTOF). Active compounds detected overall included caffeine (31.0%), quinine/quinidine (24.7%), levamisole (11.6%), acetaminophen, (8.2%) and procaine (8.2%). These compounds were found with several drugs of abuse, such as heroin, fentanyl, methamphetamine, and cocaine. This novel information about cutting agents used to dilute or alter drugs of abuse is important to criminal investigations and in the management of acute intoxications at health centers. However, common methodologies for analysis and standard reporting practices frequently do not include cutting agents, resulting in lacking or inadequate information regarding prevalence of these substances.