Flavor components in tobacco capsules identified through non-targeted quantitative analysis.

Tobacco flavors increase the attractiveness of a tobacco brand and ultimately promote addiction. Information about what flavor and how much flavor is in flavor capsules can provide an effective way to regulate tobacco flavor. In this study, 128 flavor chemicals were identified and quantified by gas chromatography-mass spectrometry using libraries and authentic standards. Validation of the developed method was performed for interference, detection limits, calibration curves, accuracy, and precision. Menthol was the main ingredient in all capsules, and the carcinogenic pulegone was detected. Detected menthofuran, benzyl alcohol, geraniol, and eugenol cause toxic or severe irritation, and detected lactones can increase nicotine addiction by inhibiting nicotine metabolism in smokers. Margin of exposures for carcinogenic pulegone and non-carcinogenic menthol were well below safety thresholds, indicating a significant risk of inhalation exposure. It is desirable to prohibit the use of flavor capsules in consideration of human risk.

Qualitative and quantitative comparison of flavor chemicals in tobacco heating products, traditional tobacco products and flavoring capsules.

A gas chromatography-mass spectrometric (GC-MS) method was developed for the qualitative and quantitative analysis of flavor chemicals in tobacco heating products (THPs), traditional tobacco products (TTPs) and their flavoring capsules. A total of 283 compounds were identified through non-target analysis, and the final 302 compounds were selected to develop an analytical method. The lower limits of detection (LOD) of analytes were 0.00074-12 mg/kg and their LOD range was wide depending on the presence or absence in the reference cigarette. The precision of the 302 compounds was less than 24.5%, and the accuracy ranged from 80.0% to 120%. A total of 190 flavors and 5 contaminants were determined in 21 THP, 10 TTP, 8 THP capsules and 11 TTP capsules. When comparing the total flavor content of flavors per cigarette, it was in the order of THP capsule> TTP capsule ≫ THP ≫ TTP. The correlations between the 53 cigarette products and 190 flavor chemicals were analyzed using PCA. It has been demonstrated that PCA results can be a useful tool in differentiating brands and manufacturers of tobacco products.

A Sensitive Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry Method Based on Derivatization with 1-Nitro-2-Naphthaldehyde for Determination of Alkylhydrazines in Surface Water.

BACKGROUND: Alkylhydrazines are widely used in industrial fields. An analysis of alkylhydrazines in surface water is needed because these chemicals are likely to be discharged into wastewater and enter aquatic environments. OBJECTIVE: An ultra-high performance liquid chromatography (UHPLC)-tandem mass spectrometry (MS/MS) method was developed to determine the levels of five alkylhydrazines (N, N-dimethylhydrazine, ethylhydrazine, 1-isopropylhydrazine, phenylhydrazine, and 1-methyl-1-phenylhydrazine) in surface water. METHODS: This method is based on the derivatization of alkylhydrazines with 1-nitro-2-naphthaldehyde (NNA) in water. A derivatization reagent dosage of 0.5 mg NNA, a pH of 2, and a reaction time of 30 min at 40°C were determined to be the optimal conditions for UHPLC-MS/MS detection. The derivatives were injected into the LC system without additional extraction or purification steps. RESULTS: The proposed method was used under optimized conditions to detect alkylhydrazines in surface water, with the limit of quantification found to be 0.01-0.03 µg/L. The accuracy ranged from 91.0 to 106.0%, and the precision, expressed as the relative standard deviation, was less than 10%. Of the five alkylhydrazines, only N, N-dimethyl hydrazine was detected in the real samples at a concentration range of 0.010-0.041 µg/L. CONCLUSION: The developed method can be used to confirm the presence of alkylhydrazine residues in surface water and represents an important tool for evaluating the fate of alkylhydrazines in surface water. HIGHLIGHTS: A UHPLC-MSMS method was developed in order to dtermine the alkylhydrazine in surface water after derivatization without an extraction or cleanup step.

Simultaneous determination of PCBs, OCPs and PAHs in mussel by ultrasound-assisted cloudy extraction and gas chromatography-tandem mass spectrometry.

A method for the simultaneous determination in mussel of 8 polychlorinated biphenyls (PCBs), 23 organochlorine pesticides (OCPs), and 35 polycyclic aromatic hydrocarbons (PAHs), including alkyl-PAHs, was optimised using ultrasound-assisted cloudy extraction and gas chromatography-tandem mass spectrometry (GC-MS/MS). Optimal selection of the extraction solvent and the dispersing solvent contributed to a high extraction yield and a clean extract. The ranges of the lower limits of detection of PCBs, OCPs and PAHs were 0.012-0.058, 0.01-0.29 and 0.01-0.5 µg kg-1, respectively. The feasibility of the proposed method was validated by analysing standard reference materials of mussel with satisfactory results. The precision achieved by this method was in the range of 0.677-2.69% (PCBs), 1.14-6.60% (OCPs) and 0.694-7.46% (PAHs), and its accuracy was in the range of 101-104% (PCBs), 99.6-106% (OCPs) and 101-110% (PAHs). The advantages of the method include the simultaneous measurement of 66 analytes and the simplicity, low cost and high sensitivity of the procedure. When the proposed method was used to analyse the target compounds in 11 mussel samples, the analytical results displayed a concentration range of 0.41-0.45 µg kg-1 for PCBs, 0.26-6.49 µg kg-1 for OCPs, and 3.48-30.69 µg kg-1 for PAHs.

Determination of N-nitrosodimethylamine and N-nitrosomethylethylamine in drug substances and products of sartans, metformin and ranitidine by precipitation and solid phase extraction and gas chromatography-tandem mass spectrometry.

N-Nitrosodimethylamine (NDMA) has been detected in some drug substance and drug products containing sartans, ranitidine and metformin. N-nitrosodiethylamine (NDEA) has also been found to be present in some sartan medications. A method for the simultaneous detection of NDMA and NDEA in drug substances and finished products of sartans, metformin and ranitidine has been optimized using isotope dilution, clean-up procedure and gas chromatography-tandem mass spectrometry (GC-MS/MS). The purification of drug substances and excipients was efficient when utilizing precipitation and activated charcoal cartridges. Most of irbesartan, pimasartan, olmesartan, and candesartan were removed by precipitation using solubility difference, while valsartan, rosartan, metformin and ranitidine were completely removed after activated charcoal purification. Even when the extracts were injected in GC-MS/MS more than 100 times, the peak shape and sensitivity did not change, and no peak interference occurred. When a 0.10 g sample was used, the range of the lower limit of detection was 0.07-0.3 µg/kg, and the range of the lower limit of quantification was 0.3-0.9 µg/kg. The precision was in the range of 0.4-2.7 % for NDMA and 0.4-4.2 % for NDEA, and the accuracy was in the range of 95.0-105 % for NDMA and 93.6-104 % for NDEA. NDMA was detected with a concentration of 0.004 mg/kg in a valsartan and 0.012 mg/kg in a ranitidine, and NDEA was detected at concentrations of 0.009 and 0.008 mg/kg in irbesartan and rosartan. Otherwise, NDMA was detected at a concentration of 0.062 mg/kg in a fimasartan product and 0.009 mg/kg in a ranitidine product. This method is available for all drug substances and finished products of sartans; metformin and ranitidine.

Consumer exposure and risk assessment to selected chemicals of mold stain remover use in Korea.

Mold stain remover (MSR) is used to clean mold and mildew spots from surfaces and contains a variety of chemical substances. In this study, we estimated the inhalation and dermal exposures associated with the use of trigger spray MSRs, and performed screening-level risk assessments for the use of this type of product in Korea. Inhalation and dermal exposures were estimated using exposure algorithms based on exposure factors obtained from a nationwide survey of 10,000 participants and chemical analyses of the four most popular trigger spray MSRs. The hazard quotients (HQs) for noncancer risk and excess cancer risk (ECR) were calculated for each chemical. The mean inhalation exposure estimates for formaldehyde, benzene, chloroform, and carbon tetrachloride were 6.9 × 10-7, 1.7 × 10-7, 5.4 × 10-6, and 2.7 × 10-5 mg/kg/day, respectively. Dermal exposures of the chemicals were 5.7-6.5 times higher than inhalation exposures. The HQs for total exposure were all below 1, which indicated little noncancer risk from the use of MSRs. The safe ECR value of 1 × 10-6, was exceed in one subject for inhalation exposure of benzene and four subjects for dermal exposure of formaldehyde, while 19.8% for dermal exposure of benzene were above this value. Therefore, use of trigger spray MSRs in Korea should require more detailed exposure and risk assessment, especially for benzene.

Probabilistic ecological risk assessment of heavy metals using the sensitivity of resident organisms in four Korean rivers.

The environment has been continuously exposed to heavy metals by various routes, from both natural and artificial sources. In particular, heavy metals in water can affect aquatic organisms adversely, even at very low concentrations, and can lead to the disturbance of the ecosystem balance and biodiversity. Ecological risk assessments are conducted to protect the environment from such situations, primarily by deriving the predicted no-effect concentration (PNEC) from the species sensitivity distribution (SSD). This study developed the SSDs based on the species living in Korean freshwater for four heavy metals including cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn). The species compositions of the SSDs were examined, and three types of PNECs were derived by applying different assessment factors (AF). In addition, the occurrence and concentrations of heavy metals in Korean rivers were investigated, and the ecological risk assessment was carried out to compare the SSDs with the environmental concentrations. The SSDs were developed using a sufficient number of species, but the missing data of plants and insects provided an incomplete species composition. The results show that Cd and Pb in the environmental concentrations of rivers would not cause any risk to aquatic organisms from the derived PNEC. However, some organisms might be adversely affected by the concentrations of Zn, and a small amount of risk was expected under the conservative PNEC. The distribution of Cu in the rivers was not considered to be safe for aquatic organisms because the average environmental concentrations potentially affected the proportion of the SSD, and the environmental concentrations exceeded the PNECs. The concentrations of Cu and Zn in industrial waters indicated a considerable risk to aquatic organisms, and the probability of exceeding the PNECs appeared to be quite high. Therefore, this study indicates that additional actions and parallel field studies are required based on the risk posed to aquatic organisms by Cu and Zn in four Korean rivers.

Simultaneous determination of 15 BTEX hydroxyl biomarkers in urine by headspace solid-phase microextraction gas chromatography-mass spectrometry.

Benzene (B), toluene (T), ethylbenzene (E), o-, m- and p-xylene (o-, m-, p-X) are ubiquitous and frequently exposed to human throughout the environment. Previously published test methods for phenolic biomarkers are not sensitive enough to be detected in most general population groups and require a lot of labor. A simple and convenient headspace solid-phase microextraction (HS-SPME) gas chromatography-mass spectrometry method was described for the simultaneous determination of 15 hydroxyl biomarkers of BTEX in urine. Hydroxyl biomarkers in urine were vaporized and adsorbed onto a selected fiber after enzyme hydrolysis with ß-glucuronidase/arylsulfatase. The optimal HS-SPME conditions were achieved with an 85-µm-carboxen-polydimethylsiloxane fiber, an extraction temperature of 70 °C, a heating time of 30 min, and a pH of 4.0. The desorption was performed for 1 min at 250 °C. Under the established conditions, the lowest limits of detection were from 0.02 to 0.15 µg/L in 5.0 mL of urine, and the intra- and inter-day relative standard deviations were less than 12.7% at 0.5, 2.0, 50, and 200 µg/L. The calibration curve demonstrated good linearity with greater than r2 = 0.99 in synthetic urine. This method is convenient, simple, environmentally friendly, and amenable to automation.

Identification and determination of disinfection byproducts in chlorine-containing household cleansing products.

Seven halogenated volatile organic compounds (HVOCs) and two haloacetic acids were detected and quantified in 15 household products, including sodium hypochlorite, by gas chromatography-mass spectrometry (GC-MS). Chloroform was detected in a range of 0.2-30.2 mg kg-1 in all products, and carbon tetrachloride was observed in 13 samples in a range of 0.05-352 mg kg-1. Dichloroacetic acid and trichloroacetic acid were also detected up to 94 and 146 mg kg-1 in household products. The estimated human exposures of chloroform, carbon tetrachloride, dichloroacetic acid and trichloroacetic acid were calculated to 0.041, 0.240, 0.913 and 2.39 mg/kg/day by the exposure algorithm from the Japan National Institute of Technology and Evaluation, respectively. According to the calculated result, the total estimated human exposure of chloroform were determined to exceed the tolerable concentration of inhalation exposure presented by the World Health Organization. The DBPs should be controlled to the lowest concentrations in the chlorine-containing household cleansing products.

Determination of volatile organic compounds including alcohols in refill fluids and cartridges of electronic cigarettes by headspace solid-phase micro extraction and gas chromatography-mass spectrometry.

An analytical method for the detection of 14 volatile organic compounds (VOCs) was developed to investigate VOCs in refill fluids and cartridges of electronic cigarettes (EC) using headspace solid-phase micro extraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). In total, 14 VOCs were identified and quantified in 283 flavored liquids, 21 nicotine liquids, and 12 disposable cartridges. The detected concentration ranges of the VOCs are as follows: benzene (0.008-2.28 mg L-1), toluene (0.006-0.687 mg L-1), ethylbenzene (0.01-1.21 mg L-1), m-xylene (0.002-1.13 mg L-1), p-xylene (0.007-2.8 mg L-1), o-xylene (0.004-2.27 mg L-1), styrene (0.011-0.339 mg L-1), ethyl acetate (0.3-669.9 mg L-1), ethanol (16-38,742 mg L-1), methanol (66-3375 mg L-1), pyridine (0.077-99.7 mg L-1), acetylpyrazine (0.077-147 mg L-1), 2,3,5-trimethylpyrazine (0.008-96.8 mg L-1), and octamethylcyclotetrasiloxane (0.1-57.2 mg L-1). Benzene, toluene, ethylbenzene, m-xylene, p-xylene, and o-xylene coexisted in samples, which may have originated from the use of petrogenic hydrocarbons as an extraction solvent for flavor and nicotine from natural plants. The maximum detected concentrations of benzene, methanol, and ethanol in liquid samples were found in quantities higher than their authorized maximum limits as residual solvents in pharmaceutical products.

Sensitive Determination of Volatile Organic Compounds and Aldehydes in Tattoo Inks.

As the popularity of body art including tattoo ink has increased, the safety associated with it has become an important interest. In this study, twenty volatile organic compounds (VOCs) and two aldehydes in tattoo inks were identified and quantified. Headspace and gas chromatography-mass spectrometry (HS GC-MS) for the VOCs and HS GC-MS based on derivatization with 2,2,2-trifluoroethylhydrazine (TFEH) for aldehydes was developed. Benzene, chloroform, toluene, ethylbenzene, m-xylene, p-xylene, o-xylene, propylbenzene, chlorobenzene, tert-butylbenzene, 1,3,5-trimethylbenzene, styrene, 1,2,4-trimethylbenzene, 2-chlorotoluene, 4-chlorotoluene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene and isopropyl alcohol were detected with the concentration range of 0.02-207,000 mg/kg in 16 different tattoo inks. Formaldehyde and acetaldehyde were detected with the concentration range of 0.4-308 mg/kg in the same samples. Our analytical results represent solvents used intentionally or non-intentionally in tattoo inks, and thus they may provide important information for national regulation.

A new derivatization approach with D-cysteine for the sensitive and simple analysis of acrylamide in foods by liquid chromatography-tandem mass spectrometry.

A liquid chromatography-tandem mass spectrometry method (LC-MS/MS) was developed in order to determine the amount of acrylamide in foods after derivatization with d-cysteine. The sulfhydryl group of d-cysteine was added at the ß-site double bond of acrylamide to form 2-amino-3-(3-amino-3-oxo-propyl)sulfanyl-propanoic acid. Deuterated acrylamide (acrylamide-d3) was chosen as the internal standard (IS) for analyzing the food samples. Acrylamide was extracted from 2.0 g of food sample with 6 mL of methylene chloride, and the organic extract was diluted with 3 mL of hexane, and then the analyte was back-extracted with 0.5 mL of pure water. The derivatization of acrylamide was performed in the water extract. The best reaction conditions (3.0mg of d-cysteine, a pH 6.5, a reaction temperature of 90°C, and a heating time of 50 min) were established by the variation of parameters. The formed derivative was injected into the LC-MS/MS without further extraction or purification procedures. Separation and detection were improved with the use of an ion-pairing reagent of perfluorooctanoic acid. Under the established conditions, the limits of detection and the limits of quantification were 0.04 µg/kg and 0.14 µg/kg, respectively, and the inter-day relative standard deviation was less than 8% at concentrations of 20 and 100 µg/kg. The method was successfully applied to determine the amount of acrylamide in potato chips, French fries, and coffee.

Ultra trace level determinations of acrylamide in surface and drinking water by GC-MS after derivatization with xanthydrol.

A sensitive GC-MS method has been established for the determination of acrylamide in surface and drinking water based on derivatization with xanthydrol. Deuterated acrylamide (acrylamide-d3 ) was chosen as the internal standard for analyzing the water sample. The derivatization of acrylamide was performed directly in water, and the best reaction conditions (xanthydrol of 1.6 mM, HCl concentration of 0.05 M, reaction for 30 min at ambient temperature) were established by variation of parameters. Under the established conditions, the detection and quantification limits were 3.0 and 9.7 ng/L, respectively, and the interday RSD was less than 8% at concentrations of 20 and 100 ng/L.

Simultaneous determination of 2-naphthol and 1-hydroxypyrene in fish and shellfish contaminated with crude oil by gas chromatography-mass spectrometry.

This paper describes a gas chromatography-mass spectrometric method of l-hydroxypyrene (1-HOP) and 2-naphthol (2-NAP) in fish and shellfish. Alkali hydrolysis method in this study was chosen and optimized to the reaction condition for 90 min at 90°C in a 2.0M KOH solution. For five independent determinations at 0.2 and 1.0 µg/kg, the coefficient of variation was less than 5.1%. This method was used to assess the long-term influence of spilled crude oil on marine ecosystems and analyze fifty-two shellfish samples taken in the near of the accident region of the Hebei Spirit oil spill. 2-NAP and 1-HOP were detected in the mean concentration range of 0.09-12.42 and 0.03-0.06 µg/kg, respectively. 2-NAP was detected in a high concentration range in shellfishes gathered in 2 months after the accident and it decreased rapidly to 6 months after that. The results showed that 2-NAP might be an important biomarker in biota contaminated with crude oil.

Sensitive and robotic determination of bromate in sea water and drinking deep-sea water by headspace solid-phase micro extraction and gas chromatography-mass spectrometry.

A robotic method has been established for the determination of bromate in sea water and drinking deep-sea water. Bromate in water was converted into volatile derivative, which was measured with headspace solid-phase micro extraction and gas chromatography-mass spectrometry (HS-SPME GC-MS). Derivatization reagent and the HS-SPME parameters (selection of fibre, extraction/derivatization temperature, heating time and; the morality of HCl) were optimized and selected. Under the established conditions, the detection and the quantification limits were 0.016 µg L(-1) and 0.051 µg L(-1), respectively, and the intra- and inter-day relative standard deviation was less than 7% at concentrations of 1.0 and 10.0 µg L(-1). The calibration curve showed good linearity with r(2)=0.9998. The common ions Cl(-), NO(3)(-), SO(4)(2-), HPO(4)(2-), H(2)PO(4)(-), K(+), Na(+), NH(4)(+), Ca(2+), Mg(2+), Ba(2+), Mn(4+), Mn(2+), Fe(3+) and Fe(2+) did not interfere even when present in 1000-fold excess over the active species. The method was successfully applied to the determination of bromate in sea water and drinking deep-sea water.

Simultaneous determination of 2-naphthol and 1-hydroxy pyrene in urine by gas chromatography-mass spectrometry.

A gas chromatography-mass spectrometric (GC-MS) method was developed for the determination of 2-naphthol (2-NAP) and 1-hydroxypyrene (1-HOP) in human urine. Extraction from urine after the enzyme hydrolysis with ß-glucuronidase/arylsulfatase was achieved with a liquid extraction using 5 mL of pentane. After addition of 50 µL of N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide (MTBDMSTFA) to prevent the loss of 2-NAP during drying, the extract was completely dried and derivatized with MTBDMSTFA for 30 min at 60 °C. The accuracies were in the range of 96-109% at a concentration of 0.5, 10 and 25 µg/L and their precisions were less than 15%. Method detection limits of 2-NAP and 1-HOP were 0.07 and 0.01 µg/L, respectively. This method was used to analyze twenty urine samples, and they were found in the concentration range <0.07-13.7 µg/L (2-NAP) and <0.01-0.88 µg/L (1-HOP). The concentrations of 2-NAP and 1-HOP were well correlated to those of naphthalene and pyrene in blood, respectively.