Triazole Fungicide Residues and Their Inhibitory Effect on Some Trichothecenes Mycotoxin Excretion in Wheat Grains

Wheat is one of the global strategic crops and ranks third in terms of cereals production. Wheat crops are exposed to many fungal infections during their cultivation stages, some of which have the ability to secrete a number of toxic secondary metabolites that threaten the quality of the grains, consumer health, producer economics, and global trade exchange. Fifty-four random samples were collected from wheat which originated from different countries. The samples included 14 types of soft wheat to study the extent of their contamination with deoxynivalenol (DON) and T-2 toxin by auto-ELISA technology and r-biopharm microtiter plate. All samples were contaminated with DON toxin except one sample, and the values ranged between 40.7 and 1018.8 µg/kg⁻¹. The highest contamination rates were in Lithuanian wheat and the lowest was in Indian wheat. Meanwhile, the highest average level of T-2 toxin contamination was in Lithuanian wheat grains with 377.4 µg/kg⁻¹, and the lowest average was 115.3 µg/kg⁻¹ in Polish wheat. GC-MS/MS and multiple reaction monitoring mode (MRM) were used to detect 15 triazole derivatives in the collected samples, which may be used to combat fungal diseases on wheat during the growing season. Only 9 derivatives were found: simeconazole, penconazole, hexaconazole, cyproconazole, diniconazole, tebuconazole, metconazole, fenbuconazole, and difenoconazole. These derivatives varied according to the origin of the wheat samples as well as their concentration, whereas another 6 derivatives were not detected in any samples. A direct inverse relationship was found between the DON concentration in the samples and the residues of simeconazole, penconazole, diniconazole, tebuconazole, metconazole, fenbuconazole, and difenoconazole, and the T-2 toxin showed the same relationship except for tebuconazole. The safe and rational use of some triazole derivatives may be a new approach and a promising strategy to not only reduce plant diseases and their problems, but also to get rid of some mycotoxins as grain contaminants.     

非手性-手性色谱-预测多反应监测法分析中药毛前胡的化学成分

中药毛前胡为伞形科植物短片藁本Ligusticum brachylobum Franch.的干燥根,主要用于治疗风热咳嗽痰多、痰热喘满、咯痰黄稠等证,富含香豆素类化学成分,含有多组对映异构体和非对映异构体.为了深入研究毛前胡的化学成分组成,特别是对映异构体的组成,研究建立了非手性-手性色谱-预测多反应监测法(achir...     

气相色谱-串联质谱法同时检测尿液中15种有毒生物碱

在气相色谱-串联质谱(GC-MS/MS)多反应监测(MRM)模式下,建立了对尿液中八角枫碱、芦竹碱、毒扁豆碱、毛果芸香碱、哈尔碱、氧化苦参碱、黄华碱、钩吻素子、钩吻碱、延胡索乙素、吴茱萸碱、血根碱、白屈菜红碱、士的宁和马钱子碱15种有毒生物碱的定性定量分析。对样品前处理、色谱、质谱条件进行了优化。在优化条件下,毒扁豆碱、哈尔碱、钩吻素子和士的宁在20~800μg/L范围内线性关系良好,其余生物碱在40~800μg/L范围内线性关系良好,相关系数均不小于0.993 2。在高、中、低3种加标水平下,除八角枫碱的平均回收率为60.0%~68.3%外,其余14种生物碱的平均回收率为81.9%~114.4%,各生物碱的相对标准偏差(RSD)不大于17.6%。方法的检出限(LOD)为4~20μg/L,定量下限(LOQ)为10~40μg/L。该方法操作简便、快捷、灵敏,适用于中毒患者尿液中有毒生物碱成分的检测。     

Analytical techniques for wine analysis: An African perspective; a review

Analytical chemistry is playing an ever-increasingly important role in the global wine industry. Chemical analysis of wine is essential in ensuring product safety and conformity to regulatory laws governing the international market, as well as understanding the fundamental aspects of grape and wine production to improve manufacturing processes. Within this field, advanced instrumental analysis methods have been exploited more extensively in recent years. Important advances in instrumental analytical techniques have also found application in the wine industry. This review aims to highlight the most important developments in the field of instrumental wine and grape analysis in the African context. The focus of this overview is specifically on the application of advanced instrumental techniques, including spectroscopic and chromatographic methods. Recent developments in wine and grape analysis and their application in the African context are highlighted, and future trends are discussed in terms of their potential contribution to the industry.     

Optimization and application of methods of triacylglycerol evaluation for characterization of olive oil adulteration by soybean oil with HPLC-APCI-MS-MS

Triacylglycerols (TAGs) are the main constituents of vegetable oils where they occur in complex mixtures with characteristic distributions. Mass spectrometry using an atmospheric pressure chemical ionization interface (APCI-MS) run in positive mode and an Ion Trap mass analyser were applied in the study of olive and soybean oils and their mixtures. Direct injections of soybean and olive oil solutions allowed the identification of ions derived from the main TAGs of both oils. This procedure showed to be a simple and powerful tool to evaluate mixtures or addition of soybean to olive oil. TAG separation was optimized by high performance liquid chromatography (HPLC) using an octadecylsilica LiChrospher column (250 mm × 3 mm; 5 μm) and a gradient composed of acetonitrile and 2-propanol allowed the separation of the main TAGs of the studied oils. APCI vaporization temperature was optimized and best signals were obtained at 370 °C. Multiple reaction monitoring (MRM) employing the transition of the protonated TAG molecules ([M+H]⁺) to the protonated diacylglycerol fragments ([M+H−R]⁺) improved the selectivity of TAG detection and was used in quantitative studies. Different strategies were developed to evaluate oil composition following TAG analysis by MRM. The external standard calibration and standard additions methods were compared for triolein quantification but the former showed to be biased. Further quantitative studies were based on the estimates of soybean and olive oil proportions in mixtures by comparison of TAG areas found in mixtures of known and unknown composition of both oils. Good agreement with expected or labeled values was found for a commercial blend containing 15% (w/w) of olive oil in soybean oil and to a 1:1 mixture of both oils, showing the potential of this method in characterizing oil mixtures and estimating oil proportions. Olive oils of different origins were also evaluated by mass spectra data obtained after direct injections of oil solutions and principal component analysis (PCA). Argentinean olive oils were clustered in a different area of the principal components plot (PC2 × PC1) in comparison with European olive oils. The commercial blend containing 15% (w/w) of olive oil in soybean oil appeared in a completely different area of the graphic, showing the potential of this method to screen out for olive oil adulterations.     

MALDI-target integrated platform for affinity-captured protein digestion

To address immunocapture of proteins in large cohorts of clinical samples high throughput sample processing is required. Here a method using the proteomic sample platform, ISET (integrated selective enrichment target) that integrates highly specific immunoaffinity capture of protein biomarker, digestion and sample cleanup with a direct interface to mass spectrometry is presented. The robustness of the on-ISET protein digestion protocol was validated by MALDI MS analysis of model proteins, ranging from 40 fmol to 1 pmol per nanovial. On-ISET digestion and MALDI MS/MS analysis of immunoaffinity captured disease-associated biomarker PSA (prostate specific antigen) from human seminal plasma are presented.     

Recent advances in sample preparation techniques and methods of sulfonamides detection – A review

Sulfonamides (SAs) have been the most widely used antimicrobial drugs for more than 70 years, and their residues in foodstuffs and environmental samples pose serious health hazards. For this reason, sensitive and specific methods for the quantification of these compounds in numerous matrices have been developed. This review intends to provide an updated overview of the recent trends over the past five years in sample preparation techniques and methods for detecting SAs. Examples of the sample preparation techniques, including liquid–liquid and solid-phase extraction, dispersive liquid–liquid microextraction and QuEChERS, are given. Different methods of detecting the SAs present in food and feed and in environmental, pharmaceutical and biological samples are discussed.     

气相色谱-串联质谱法快速测定调味品中3种糠醛类物质

建立了同时测定调味品中糠醛、5-甲基糠醛和5-羟甲基糠醛的气相色谱-串联质谱法(GC-MS/MS)。对样品的前处理方法及GC-MS/MS分析条件进行优化,样品经乙酸乙酯萃取,GC-MS/MS多反应监测模式(MRM)进行测定。3种糠醛类物质在0.001～20 mg/L范围内均呈良好的线性关系,相关系数为0.999 0～0.999 5;检出限(S/N=3)均为0.005 mg/kg,加标回收率为86%～95%。该法简便、快速、溶剂用量少,可消除调味品中复杂基质的干扰,结果准确可靠、灵敏度高,适用于调味品中3种糠醛类物质的同时测定。     

Rapid screening and characterization of drug metabolites using a multiple ion monitoring-dependent MS/MS acquisition method on a hybrid triple quadrupole-linear ion trap mass spectrometer

A novel LC/MS/MS method that uses multiple ion monitoring (MIM) as a survey scan to trigger the acquisition of enhanced product ions (EPI) on a hybrid quadrupole-linear ion trap mass spectrometer (Q TRAP) was developed for drug metabolite identification. In the MIM experiment, multiple predicted metabolite ions were monitored in both Q1 and Q3. The collision energy in Q2 was set to a low value to minimize fragmentation. Results from analyzing ritonavir metabolites in rat hepatocytes demonstrate that MIM-EPI was capable of targeting a larger number of metabolites regardless of their fragmentation and retained sensitivity and duty cycle similar to multiple reaction monitoring (MRM)-EPI. MIM-based scanning methods were shown to be particularly useful in several applications. First, MIM-EPI enabled the sensitive detection and MS/MS acquisition of up to 100 predicted metabolites. Second, MIM-MRM-EPI was better than MRM-EPI in the analysis of metabolites that undergo either predictable or unpredictable fragmentation pathways. Finally, a combination of MIM-EPI and full-scan MS (EMS), as an alternative to EMS-EPI, was well suited for routine in vitro metabolite profiling. Overall, MIM-EPI significantly enhanced the metabolite identification capability of the hybrid triple quadrupole-linear ion trap LC/MS.     

First screening method for the simultaneous detection of seven allergens by liquid chromatography mass spectrometry

The development of a multi-method for the detection of seven allergens based on liquid chromatography and triple-quadrupole tandem mass spectrometry in multiple reaction mode is described. It is based on extraction of the allergenic proteins from a food matrix, followed by enzymatic digestion with trypsin. The chosen marker peptides were implemented into one method that is capable of the simultaneous detection of milk, egg, soy, hazelnut, peanut, walnut and almond. This method has been used to detect all seven allergenic commodities from incurred reference bread material, which was baked according to a standard recipe from the baking industry. Detected concentrations ranged from 10 to 1000 μg/g, demonstrating that the mass spectrometric based method is a useful tool for allergen screening.