A Rapid Direct Solvent Extraction Method for the Extraction of 2-Dodecylcyclobutanone from Irradiated Ground Beef Patties Using Acetonitrile

Abstract: The amount of irradiated beef in the U.S. market is growing, and a reliable, rapid method is needed to detect irradiated beef and quantify the irradiation dose. The official analytical method (BS EN 1785 2003) that has been adopted by the European Union is time consuming. The objective of this study was to develop a rapid method for the analysis of 2-dodecylcyclobutanone (2-DCB) in irradiated beef. A 5 g sample of commercially irradiated ground beef patty (90/10) was extracted with n-hexane using a Soxhlet apparatus or with acetonitrile via direct solvent extraction. The Soxhlet hexane extract was evaporated to dryness, and the sample was dissolved in a mixture of ethyl acetate and acetonitrile (1:1). The defatted extract was purified with a 1 g silica cartridge. Another 5 g aliquot of the same patty was mixed with 50 mL acetonitrile and either blended for 1 min with a hand blender or crushed for 10 min with a glass rod. The extraction procedure was repeated 3 times, and the acetonitrile was collected and evaporated to dryness. Eluants from both methods were concentrated under nitrogen and injected into a gas chromatography-mass spectrometry. The 2-DCB concentration in the commercial samples was 0.031 ± 0.0026 ppm (n = 5) for the Soxhlet method and 0.031 ± 0.0025 ppm (n = 10) for direct solvent extraction. Recovery of 2-DCB from spiked beef samples in the direct solvent extraction method was 93.2 ± 9.0% (n = 7). This study showed that the direct solvent extraction method is simple and as efficient and reproducible as the Soxhlet method.     

Levels of 2-dodecylcyclobutanone in ground beef patties irradiated by low-energy X-ray and gamma rays

Food irradiation improves food safety and maintains food quality by controlling microorganisms and extending shelf life. However, acceptance and commercial adoption of food irradiation is still low. Consumer groups such as Public Citizen and the Food and Water Watch have opposed irradiation because of the formation of 2-alkylcyclobutanones (2-ACBs) in irradiated, lipid-containing foods. The objectives of this study were to measure and to compare the level of 2-dodecylcyclobutanone (2-DCB) in ground beef irradiated by low-energy X-rays and gamma rays. Beef patties were irradiated by low-energy X-rays and gamma rays (Cs-137) at 3 targeted absorbed doses of 1.5, 3.0, and 5.0 kGy. The samples were extracted with n-hexane using a Soxhlet apparatus, and the 2-DCB concentration was determined with gas chromatography-mass spectrometry. The 2-DCB concentration increased linearly (P < 0.05) with irradiation dose for gamma-ray and low-energy X-ray irradiated patties. There was no significant difference in 2-DCB concentration between gamma-ray and low-energy X-ray irradiated patties (P > 0.05) at all targeted doses.     

Effect of cooking on radiation-induced chemical markers in beef and pork during storage

Raw and cooked beef and pork loins were irradiated at 0 or 5 kGy. The radiation-induced marker compounds, such as hydrocarbons, 2-alkylcyclobutanones (2-ACBs), and sulfur volatiles, were determined after 0 and 6 mo of frozen storage. Two hydrocarbons (8-heptadecene [C(17:1)] and 6,9-heptadecadiene [C(17:2)]) and two 2-ACBs (2-dodecylcyclobutanone [2-DCB] and 2-tetradecylcyclobutanone [2-TCB]) were detected only in irradiated raw and cooked meats. Although precooked irradiated meats produced more hydrocarbons and 2-ACBs than the irradiated cooked ones, the amounts of individual hydrocarbons and 2-ACBs, such as 8-heptadecene, 6,9-heptadecadiene, 2-DCB, and 2-TCB, were sufficient enough to detect whether the meat was irradiated or not. Dimethyl disulfide and dimethyl trisulfide were also determined only in irradiated meats but dimethyl trisulfide disappeared after 6 mo of frozen storage under oxygen-permeable packaging conditions. The results indicated that 8-heptadecene, 6,9-heptadecadiene, 2-DCB, 2-TCB, and dimethyl disulfide, even though they were decreased with storage, could be used as marker compounds for the detection of irradiated beef and pork regardless of cooking under the frozen conditions for 6 mo. PRACTICAL APPLICATION: Radiation-induced chemical changes such as specific hydrocarbons, 2-ACBs, and sulfur volatiles may be used as potential identification markers by regulatory authorities to confirm irradiation history of frozen stored raw or cooked beef and pork.     

GC-MS法测定蔬菜中3，5，6-三氯-2羟基吡啶

建立蔬菜中毒死蜱代谢物3,5,6- 三氯-2 羟基吡啶(3,5,6-trichloro-2-pyridinol,TCP)的气相色谱- 质谱检测方法。样品经丙酮提取,正己烷去除杂质,二氯甲烷反萃取,过无水硫酸钠去除水分,浓缩后乙酸乙酯溶解,再用N-(特丁基二甲基硅烷基)-N- 甲基三氟乙酰胺(MTBSTFA)衍生,正己烷定容,经气相色谱- 质谱检测,外标法定量。方法的检出限为8.3μg/kg,加标回收率为70.4%～107.6%,RSD 为4.3%～8.7%。在5～500μg/L 的范围内线性范围良好,相关系数大于0.99。该方法通用性强,灵敏度高,可用于蔬菜中TCP 的检测。     

Solid-phase micro extraction of food irradiation marker 2-dodecylcyclobutanone (2-DCB) from chicken jerky treated with glycerol

The food irradiation marker, 2-dodecylcyclobutanone (2-DCB), assayed by SPME provides a fast and simple method to estimate the irradiation history of fat-containing food products. The SPME conditions were optimized to maximize the extraction of 2-DCB from chicken jerky treats (CJT) irradiated at low (5 kGy) and high (50 kGy) doses. The extracted 2-DCB was measured using GC-MS in selected ion mode (m/z 98, and 112). Water dilution (1:5) was needed to mobilize 2-DCB and allow partition to the headspace form the CJT matrix. Increasing the incubation temperature to 80 °C resulted in higher response. Spiking control jerky samples with 2-DCB from 10 to 150 ng/g CJT compared with spiking water revealed a significant food matrix effect. This method provides a fast, simple, and environmental friendly alternative for the existing solvent extraction methods.     

In vitro antioxidant/free radical scavenging and antibacterial properties of endemic oregano and thyme extracts from Greece

The present investigation was to evaluate the antioxidant and antibacterial activities of hexane and methanol extracts from Origanum vulgare ssp. hirtum and Thymus vulgaris (Komotini, Greece). The methanol extracts of oregano and thyme against DPPH radical were more active than the hexane extracts (mean values 0.94 and 0.47, respectively) and oregano exhibited stronger activity than thyme (mean values 0.82 and 0.55, respectively). The results from the β-carotene/linoleic acid assay showed that all plant extracts inhibited linoleic acid oxidation up to 70.78±1.17%. The oregano extracts exhibited the strongest inhibition against Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus using the disc diffusion assay. The chemical composition of the hexane and methanol extracts, by using GC-MS, showed that carvacrol, thymol, and p-cymene were the most prominent compounds. The methanol extract of oregano was found the most potent antioxidant with the highest content of total phenolics (138.92 mg GA/g extract) and carvacrol (76.7%).     

Study of chloropropanols in soy sauce by gas chromatography-triple quadrupole mass spectrometry with coupled column separation without derivatisation

A qualitative and quantitative determination method for chloropropanols in soy sauce was developed by GC-MS/MS with coupled column separation without derivatisation. The target compounds were 1,3-dichloropropan-2-ol (1,3-DCP), 2,3-dichloropropan-1-ol (2,3-DCP), 3-monochloropropane-1,2-diol (3-MCPD) and 2-monochloropropane-1,3-diol (2-MCPD). 3-MCPD-d₅ was used as an isotope internal standard for MCPDs and 1,3-DCP-d₅ for DCPs. After spiking with internal standards and mixed with 1?g of Extrelut? NT, about 1?g of the sample was washed by 4?ml of hexane and the analytes were eluted with 15?ml of 95% (v/v) ethyl ether/hexane mixture. The concentrated extract was directly injected without derivatisation, separated by a coupled column – a 3?m Innowax (polyethylene glycol) combined with a 30?m DB-5?ms ((5%-phenyl)-methylpolysiloxane) by a quartz capillary column connector – and detected by GC-MS/MS. The limits of detection (LODs) in the sample matrix were 1.0, 2.5, 5.0 and 5.0?µg?kg^?1 for the above chloropropanols, respectively. The relative proportions of 2-MCPD/3-MCPD ranged from 0.19 to 3.74 in soy sauce samples. 2,3-DCP and 2-MCPD were more stable than 1,3-DCP and 3-MCPD under alkaline condition. The levels of chloropropanols can be decreased by an alkaline treatment process.     

In vitro inhibitory effect of oriental melon (Cucumis melo L. var. makuwa Makino) seed on key enzyme linked to type 2 diabetes: Assessment of anti-diabetic potential of functional food

As the world’s population continues to increase, the agricultural discards of plant origin have attracted considerable attention for various purposes in the pharmaceutical and food industry. The objective of present study was to evaluate the potential of oriental melon (Cucumis melo L. var. makuwa Makino) seed for management of hyperglycaemia-linked to type 2 diabetes. Ethanol and hexane extracts from oriental melon seed were used to evaluate their inhibitory activities against α-glucosidase and α-amylase. Low phenolic-containing hexane extract exhibited much higher inhibitory activities against α-glucosidase and α-amylase than ethanol extract. The GC–MS result revealed that hexane extract constituted linoleic acid (29.6%), oleic acid (17.3%), and palmitic acid (6.5%). At high concentration, hexane extract exhibited strong inhibitory activities against α-glucosidase (35.3%) and α-amylase (61.8%). These in vitro studies indicated that hexane extract of oriental melon seed could be used as a potent alternative for controlling type 2 diabetes.     

Anti-obesity role of adzuki bean extract containing polyphenols: in vivo and in vitro effects

BACKGROUND: The aim of this work was to evaluate the effects of polyphenol‐rich adzuki bean extract on lipid metabolism, triglyceride accumulation and proinflammatory cytokine secretion in vivo and in vitro. RESULTS: For the in vivo study, rats were divided into four groups: group C was fed a control diet, group A was fed the control diet with 1% adzuki bean extract, group CF was fed a high fat diet, and group AF was fed a high fat diet with 1% adzuki bean extract. For the in vitro study, the ability of adzuki bean extract to suppress triglyceride incorporation, glycerol phosphate dehydrogenase activity and inflammatory response was investigated in cultured human adipocytes. Data from the animal study showed that adzuki bean extract improved lipid metabolism in both the normal and high‐fat diet groups. Adzuki bean extract treatment in the high‐fat group resulted in significant reductions in total hepatic lipid accumulation and lipid secretion into the feces. Incubation of adipocytes with adzuki bean extract significantly decreased triglyceride accumulation, glycerol phosphate dehydrogenase activity and inflammatory responses without affecting cell viability. CONCLUSION: The results of this study demonstrate that adzuki bean extract has high potential to serve as a natural anti‐obesity agent. Copyright © 2012 Society of Chemical Industry     

Controlling the formation of indole and skatole in in vitro rumen fermentations using condensed tannin

Indole and skatole are formed in the rumen from the fermentation of tryptophan and have been correlated to the presence of undesirable pastoral flavours in meat from grazing ruminants. A series of four in vitro rumen fermentation experiments was carried out to determine the effectiveness of condensed tannin (CT) for reducing the formation of indole and skatole. Experiment 1 utilised fresh white clover (WC; Trifolium repens) in ratios with the CT‐containing forage Lotus pedunculatus (LP; 97 g CT kg^?1 dry matter (DM)). Increasing the ratio of LP to WC decreased the formation of indole and skatole. Experiments 2 and 3 used extracts of CT from LP and grape seed added to incubations of fresh non‐CT‐containing WC or perennial ryegrass (PRG; Lolium perenne). Including the CT extracts in incubations at 40 and 80 g kg^?1 DM was more effective at reducing indole and skatole formation than lower concentrations of CT extract (P < 0.05). Including fresh LP in ratios with WC gave a linear decrease in indole and skatole concentration (indicating dilution), while including a CT extract in the incubations gave an exponential decrease in indole and skatole concentration (suggesting binding). Experiment 4 elucidated the mechanisms behind the action of CT by delayed addition of tryptophan and polyethylene glycol (PEG) to incubations of LP. Rumen microbes that were exposed to CT of LP in planta for up to 6 h and then provided with tryptophan were still able to convert tryptophan to indole and skatole. Adding PEG to incubations of LP after 6 h inhibited the activity of plant CT and increased the availability of substrate for indole and skatole formation. These studies have shown that a higher concentration of CT is more efficient for reducing indole and skatole formation and that CT contained within plants acts differently in in vitro rumen fermentations than additions of extracted CT. Under the conditions of these experiments, there was no evidence that CT contained in LP affected the protein present in WC in a mixed fermentation. Copyright © 2007 Society of Chemical Industry     

凝胶渗透色谱净化-气相色谱-串联质谱法测定辐照肉制品中2-十二烷基环丁酮

基于凝胶渗透色谱（gel permeation chromatography，GPC）净化处理，建立辐照肉制品中2-十二烷基环丁酮（2-dodecylcyclobutanone，2-DCB）的气相色谱-串联质谱（gas chromatography-tandem mass spectrometry，GC-MS/MS）检测方法。样品经正己烷超声提取、GPC净化及氮吹浓缩等步骤处理后，利用GC-MS/MS多反应监测模式进行分析。结果表明：2-DCB在质量浓度10～1 000 μg/L范围内线性良好，线性方程为y=383 709.18x－4 686.41，相关系数为0.998 3；25、100、400 μg/kg 3 个加标水平的平均回收率为78.2%～105.5%，相对标准偏差小于7.3%；检出限和定量限分别为1.8、6.0 μg/kg。该方法前处理操作简单、可实现自动化批量处理，同时具有较高灵敏度。     

Lyophilized Tea Extracts of Brickellia cavanillesii (Asteraceae): In Vitro Characterization of Biological Activity

Lyophilized Brickellia cavanillesii (LBC) tea extracts and identified chemical compounds of LBC were examined using in vitro human carcinoma liver (HepG2) cells with and without fetal bovine serum (FBS). Cells were incubated for 24 h with varying concentrations of FBS and LBC, respectively; cytotoxicity was determined spectrophotometrically using MTT (Formazan 3‐(4,5‐dimethyl‐thiazol‐2‐yl)‐2, 5‐diphenyl‐tetrazolium bromide) assay. Furthermore, the potential hypoglycemic activity of LBC tea extracts was investigated using glucose transport and metabolism proteins biomarkers. FBS (0% to 10%) increased the viability of HepG2 cells steadily with increasing concentration. Possible therapeutic effects of LBC were concentration dependent with and without FBS. The cytotoxicity of 12 identified compounds from the LBC extract suggests that the individual compounds inhibited the proliferation of HepG2 cells differentially and do not reflect the inhibition of the whole aqueous LBC. Western blot analysis of glucose facilitated transporter protein 2 (GLUT 2) expression of HepG2 cells exposed to 0 mg/mL (Control) and 0.2 mg/mL LBC for 2, 4, 6, and 24 h suggests that GLUT 2 expression was increased. Increase in GLUT 2 expression in the absence of FBS was statistically significant with time of exposure. Significant difference was observed for GLUT 2 expression between 6 and 24 h and also between 4 and 24 h at 0.2 mg/mL LBC. Results obtained indicate that LBC may exhibit antidiabetic activity. However, further studies will be necessary to clearly delineate LBC potential therapeutic benefit and biological activities in animal studies as well as other in vitro models.     

Comparative Bio-Active Compounds Determination and In Vitro Antioxidant Properties of Newly Developed Soy Mixed Wheat Flour and Traditional Wheat Flour

The aims of this study were quantitative determination of the bio-active compounds and to evaluate the in vitro antioxidant activities of methanolic extract of soy mixed wheat flour and traditional wheat flour. Soy mixed wheat flour was developed by combination of processed soy flour and wheat flour. Total phenolics, flavonoids, tannin, and proanthocyanidin contents of the crude methanolic extract were determined by ultraviolet-visible spectrophotometer. Further individual bio-active compounds were determined by high-performance liquid chromatography-diode array detector and showed (+)-catechin, vanillic acid, caffeic acid, (–)-epicatechin, p-coumaric acid, rutin hydrate, and ellagic acid in soy mixed wheat flour but only rutin in traditional wheat flour. The soy mixed product showed significantly higher concentration of bio-active compounds than traditional wheat flour. Antioxidative activities were measured through different in vitro models: phosphomolybdenum blue method, FeCl₃ reducing power, ABTS scavenging activity, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity, N,N-dimethyl-1,4-diaminobenzene free radical scavenging activity, reducing power, metal chelating power and super oxide scavenging ability. All results of in vitro antioxidant models revealed that the soy product showed significantly higher antioxidant activities than traditional wheat flour. These results suggested that soy mixed wheat flour can play the greater roles than the traditional wheat flour for different physiological activities in human body due to the presence of greater amount of bio-active compounds and can be considered as a potential antioxidant containing flour for human consumption than the traditional wheat flour.     

Mutagenicity and Acute Toxicity Evaluation of 2-Dodecylcyclobutanone

ABSTRACT: Mutagenicity and acute toxicity of 2-dodecylcyclobutanone (2-DCB), a unique radiolytic product, were evaluated. Mutagenicity was evaluated by the Ames assay using 5 standard Salmonella tester strains with S9 enzyme activation and 5 concentrations of 2-DCB. Sodium azide (NaN₃), fenaminosulf, and2-aminofluorene (2-AF) served as positive controls. The Ames assay showed no difference between the 5 concentrations of 2-DCB and the controls, including samples incubated with S9. The results indicate that 2-DCB does not produce point or frameshift mutations in Salmonella and is not activated by S9. Acute toxicity of 2-DCB was evaluated by the Microtox acute toxicity system and compared with cyclohexanone and 2-nonenal (both GRAS additives). The effective concentrations that caused a 50% reduction in light emission by Vibrio fischeri cells (EC₅₀) were; 21.72 6 14.57 ppm for 2-DCB, 37.40 6 0.45 ppm for cyclohexanone, and 1.65 6 0.26 ppm for 2-nonenal. The maximum number of cells affected by 2-DCB was 65% 6 4%, while it reached 90% to 100% for the other 2 compounds. Our results suggest that even though the EC₅₀ for 2-DCB is lower than that for cyclohexanone, it was not toxic enough to decrease light emission of V. fischeri beyond 60% to 70%. These results indicate that the potential risk from 2-DCB, if any, is very low.     

Induction of Micronuclei in Human TK6 Lymphoblasts by 2-Dodecylcyclobutanone, a Unique Radiolytic Product of Palmitic Acid

ABSTRACT:  Palmitic acid, the most abundant fatty acid in the human diet, causes oxidative DNA damage, DNA strand breakage, necrosis, and apoptosis in human and rodent cells in vitro , while excess fatty acids in the diet increase the risk of colon cancer in vivo . Irradiation of palmitic acid leads to the formation of 2-dodecylcyclobutanone (2-DCB), a unique radiolytic product formed at part-per-million levels in fats. Recent research has raised the possibility that, like palmitic acid, 2-DCB can also cause DNA strand breaks in human and rodent cells. In order to more fully understand the clastogenic potential of 2-DCB, it was tested for the ability to induce the formation of micronuclei (MN) in human TK6 lymphoblasts. TK6 lymphoblasts were exposed to 13.3, 26.5, and 53 μM of 2-DCB for 24 h, both with and without exogenous metabolic activation (EMA). The number of MN per 1000 binucleated cells was induced 2.65-fold without EMA, and 2.85-fold in the presence of EMA at the highest 2-DCB concentration of 53 μM. Cytotoxicity of the TK6 lymphoblasts treated with 53 μM 2-DCB was 51.7% in the absence of EMA, and 61.7% in the presence of EMA. Thus, like palmitic acid, 2-DCB may be weakly clastogenic against human cells in vitro . Given the amount of 2-DCB that would be consumed when compared with that of its clastogenic parent fatty acid, 2-DCB is unlikely to have any significant impact on human health.     

Condensed tannins from Lotus corniculatus and Lotus pedunculatus exert different effects on the in vitro rumen degradation of ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) protein

Condensed tannins (CT) or proanthocyanidins (PA), which occur in a restricted range of forages, have the ability to interact with proteins and enzymes and can influence the digestion of plant protein in the rumen. We compared the effects of CT extracts from Lotus corniculatus and pedunculatus on degradation of the principal leaf protein, ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco), by rumen microorganisms. Total soluble leaf protein extracted from white clover (Trifolium repens ) was incubated with fresh rumen fluid from sheep and a range of concentrations of each CT extract. The rate of degradation of the large (LSU) and small subunit (SSU) of Rubisco was quantified by fractionating the proteins in samples taken from in vitro rumen incubations using sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS‐PAGE) and imaging densitometry. To deduce the effects of the CT extracts, experiments were performed in the presence (CT inactive) and absence (CT active) of polyethylene glycol (PEG; MW 3350). The two CT extracts differed markedly in their effects on the degradation of the LSU and SSU of Rubisco. At concentrations of 0.89 and 1.79 mg CT mg ⁻¹ total soluble leaf protein, the CT extract from L pedunculatus was more effective at preventing the degradation of the LSU and SSU by rumen microorganisms than the CT extract from L corniculatus. At a concentration of 1.79 mg CT mg ⁻¹ total soluble leaf protein, the CT extracts from L corniculatus and pedunculatus prevented about 0.75 and 0.83 of the LSU and about 0.69 and 0.86 of the SSU, respectively, from being degraded. Addition of PEG removed the inhibition and almost complete degradation of these proteins occurred, as was the case in incubations without CT extracts. The results of this study suggest that the concentration of CT in the diet and the chemical structure which affects the activity of the CT needs to be considered when assessing the effects of CT on protein metabolism in ruminants. © 1999 Society of Chemical Industry     

In vitro biotransformation of OA-group and PTX-group toxins in visceral and non-visceral tissues of Mytilus chilensis and Ameghinomya antiqua

ABSTRACT

Lipophilic marine toxins (LMTs) are made up of multiple groups of toxic analogues, which are characterised by different levels of cellular and toxic action. The most prevalent groups in the southern Pacific zone are: a) okadaic acid group (OA-group) which consists of okadaic acid (OA) and dinophysistoxin-1 (DTX-1); and, b) pectenotoxin-2 (PTX2) group which consists of pectenotoxin-2 (PTX-2). The main objective of our study was to examine in vitro biotransformation of OA-group and PTX-group in the tissues of two endemic species of bivalves from southern Chile; blue mussels (Mytilus chilensis) and clams (Ameghinomya antiqua). The biotransformation processes of both groups were only detected in the digestive glands of both species using LC-MS/MS. The most frequently detected analogues were acyl derivatives (≈2.0 ± 0.1 μg ml^?1) for OA-group and PTX-2SA (≈1.4 ± 0.1 μg ml^?1) for PTX-group, with a higher percentage of biotransformation for OA-group (p < .001). In addition, simultaneous incubations of the different analogues (OA/PTX-2; DTX-1/PTX-2 and OA/DTX-1/PTX-2) did not show any interaction between the biotransformation processes. These results show that the toxicological variability of endemic species leads to biotransformation of the profile of toxins, so that these new analogues may affect people’s health.     

Validation of an alternative method for the identification of 2-dodecylcyclebutanone (2-DCB) of irradiated meats by solid-phase microextraction (SPME) gas chromatography–mass spectrometry (GC-MS)

A rapid and simple procedure to detect irradiated food containing fat is proposed. This method is based on HS-SPME coupled with GC-MS to determine the presence of a radiolytic product in irradiated meats: 2-dodecylcyclobutanone (2-DCB) and is proposed as an alternative to EN 1785:2003, which is a long and complex procedure. The qualitative confirmation method is validated on different type of meats: chicken, turkey, duck, beef, pork on both nonirradiated and irradiated samples at different dose levels (0.05, 0.12, 0.5, 1.0 and 3.0 kGy) with a biological X-ray irradiator. The validation parameters investigated are selectivity, minimum dose level (MDL), limit of detection (LOD), sensitivity and specificity. The MDL and LOD values were 0.5 kGy and 5.0 ng mL⁻¹, respectively, for all matrices. No false positives or false negatives occurred, and 100% of samples were correctly identified. The results show that HS-SPME GC-MS is suitable for routine analysis.     

气相色谱-质谱法测定纺织品中17种酚类化合物

为了解决同时测定纺织品中多种酚类化合物的问题,建立了气相色谱-质谱法(GC-MS)同时测定纺织品中17种酚类化合物的分析方法。样品用氢氧化钾溶液(2 mol/L)超声提取,将提取溶液与乙酸酐衍生化反应。衍生产物经正己烷提取后,采用GC-MS检测,选择离子模式(SIM)扫描,内标法定量分析。该方法在0.05~0.5 μg/mL范围内呈良好的线性关系,相关系数(r2)≥0.9990;方法的定量限为0.05 mg/kg,平均回收率为89.3% ~ 117.6 %,相对标准偏差小于9.3 %。实验结果表明该方法准确、灵敏,可用于纺织品中17种酚类化合物的分析测定。     

纺织品中有机锡测定的样品前处理

采用乙酸钠缓冲溶液(pH =4.0±0.1)和甲醇等体积混合构成对纺织品中有机锡化合物的协同提取体系;再以正己烷萃取四乙基硼酸钠衍生物,用气相色谱-质谱进行定性定量分析.通过对提取体系、提取方式、衍生反应条件等试验因素的优化,建立了对纺织品中5种有机锡[一丁基锡(MBT)、二丁基锡(DBT)、三丁基锡(TBT)、二辛基锡(DOT)和三苯基锡(TPhT)]的气相色谱-质谱检测方法,并对其线性关系、回收率和精密度等进行了考察.该方法简便、准确、可操作性强,适用于对各种纺织品中5种有机锡化合物的检测分析.