A pilot survey of 2- and 3-monochloropropanediol and glycidol fatty acid esters in foods on the Canadian market 2011–2013

We are presenting data on the occurrence of 2- and 3-MCPD esters and glycidol esters (MCPDEs and GEs) in more than 100 different edible fats, oils, and related products containing fats/oils, such as cookies and cooking sprays. Most of these products were purchased from retail stores in Ottawa, Canada between 2011 and 2013 in duplicate, thus allowing for evaluation of temporal trends. GEs and MCPDEs were determined by stable isotope dilution analysis using glycidol-d₅ labelled standards by LC–MS/MS in APCI mode and GC–MS in SIM mode after derivation with cyclohexanone, respectively. Unprocessed oils did not contain detectable levels of GEs or MCPDEs or contained them in trace amounts. The exception was palm oil, which contained 100–550 ng/g MCPDEs. GEs and MCPDEs content was highly variable in processed oils/fats, reaching 10.6 and 17.1 μg/g (expressed as glycidol and MCPDs equivalents, respectively). Walnut, rice bran, grape seed oils and palm oil shortening were found to have the highest levels of MCPDEs and GEs. Levels in cookies also varied greatly from 5 to 339 ng/g, expressed as glycidol equivalents and from 29 to 510 ng/g expressed as MCPD equivalents.     

Gas chromatography with mass spectrometry detection and characterization of 27 sterols in two truffle (Tuber) species

Fungal sterols (mycosterols) were investigated in seven samples of both Tuber aestivum and Tuber borchii truffles from Italy, Spain and Romania by means of gas chromatography with mass spectrometry (GC/MS). Sterol contents varied from 130 to 590 mg/100 g dry weight (T. borchii) and 110−420 mg/100 g dry weight (T. aestivum). The sterol pattern of both truffle species was dominated by ergosterol (60–85 %) and brassicasterol (4–33 %). In addition, 25 minor sterols were detected with 27 (n = 3), 28 (n = 17), 29 (n = 3), 30 (n = 2) and 31 (n = 2) carbon atoms (Limit of detection: 2 μg/100 g dry weight). Fourteen minor sterols were described for the first time in Tuber species. Ten minor compounds were detected in all samples in varying abundances, while the others were (i) exclusively detected in all samples of one species (T. borchii: fecosterol, ergosta-8-enol; T. aestivum: 24-methyleneergosta-5,22,24-trienol) or (ii) varied strongly in abundance (≥90 %). Variations in main and selected minor sterols could be partly related to different harvest times. In addition, differences in fungisterol and ergosta-5,7-dienol between the both species were attributed to different pathways in fungal sterol biosynthesis (oneway ANOVA p ≤ 0.01). Our study indicates that sterol pattern analysis could be used to differentiate different Tuber species.     

有机氯农药多残留GC-MS分析方法研究

应用Ｍａｓｌａｂ的定量软件，以选择离子扫描方式，建立了有机氯农药多残留的ＧＣ－ＭＳ定量测定方法。经方法的线性试验、精密度试验、检测限试验，验证了有机氯农药多残留ＧＣ－ＭＳ分析方法的可行性。ＰＣＮＢ和ｐｐ＇－ＤＤＴ在０．００２５～０．５０ｎｇ，α－ＨＣＨ、β－ＨＣＨ、γ－ＨＣＨ、δ－ＨＣＨ、ｏｐ＇－ＤＤＴ、ｐｐ＇－ＤＤＤ、ｐｐ＇－ＤＤＥ、ＨＣＢ在０．００２０～０．４０ｎｇ范围内呈现良好的线性关系；方法的最低检出量：ＰＣＮＢ和ｐｐ＇－ＤＤＴ为０．００２５ｎｇ，α－ＨＣＨ、β－ＨＣＨ、γ－ＨＣＨ、δ－ＨＣＨ、ｏｐ＇－ＤＤＴ、ｐｐ＇－ＤＤＤ、ｐｐ＇－ＤＤＥ、ＨＣＢ为０．００２０ｎｇ．精密度试验的变异系数满足了农药多残留痕量分析的要     

氘代同位素内标GC/MS法测定食品中3-氯-1,2-丙二醇的方法研究

目的:建立以氘代同位素内标测定食品中3-氯-1, 2 -丙二醇的GC/MS方法。方法:试样中加入d5 -3 -氯-1, 2-丙二醇氘代同位素内标,用盐溶液提取试样中的3-MCPD,采用Extrelut硅藻土进行柱层析净化试样,经七氟丁酰基咪唑衍生化后, 用毛细柱气相色谱分离,采用选择离子监测(SIM)的质谱扫描模式进行定量分析。结果: 3-氯-1,2-丙二醇检测限低于0. 01mg/kg; 各类食品样品加标0. 01mg/kg的平均回收率>85%,样品重复测定6次的CV值均小于10%。结论:该方法具有较高的灵敏度、准确度、精密度和特异性,可满足欧盟和我国法规对痕量氯丙醇检测分析的要求,适用于可能含有3-MCPD的几乎所有食品。     

GC-MS分析法在人参有机氯农药残留检测中的应用

以丙酮－饱和氯化钠溶液－石油醚的一步法提取分离技术制备样品溶液,采用ＧＣ－ＭＳ分析方法对人参中有机氯农药残留进行了测定。加标人参样品的测定结果表明：两个水平加标回收率：０．１０ｍｇ／ｋｇ添加水平时,除ＰＣＮＢ平均回收率为５８．３％,其它组分的平均回收率为７６．０％～９０．１％,相对标准差为９．３％～１５．０％;０．０５０ｍｇ／ｋｇ添加水平时,平均回收率为６２．３％～８７．２％,相对标准差为６．０％～２２．５％。应用本方法测定人参中有机氯农药残留,基本上满足了灵敏、快速、准确可靠的分析方法要求     

中山市市售猪肉(含猪内脏)残留禁用化学药品的现状及控制的研究

目的 掌握中山市市售猪肉（含猪内脏）受禁用化学药品污染的现状，提出相应的预防和控制措施，方法 采用分层按比例抽样的方法，分别对中山市的港口镇，三乡镇，沙溪镇，小榄镇，石岐城区共80份市售猪肉（含猪内脏）进行调查，采用气质联用法（GC/MS）检测，鉴别其中含有禁用化学药品的成分。结果 此次调查80个样品共检出禁用化学药品有3种，残留阳性样品5个，总残留阳性率为6.3%。其中盐酸克仑特罗阳性检出率为5.0%，N，N-二甲基硫脲和甲巯基咪唑阳性检出率均为1.3%。盐酸克仑特罗阳性样品全部来自小榄镇，N，N-二甲基硫脲和甲巯基咪唑阳性样品则来自石岐城区，港口镇，三乡镇，沙溪镇均未检出阳性样品，结论 中山市市售猪肉（含猪内脏）残留的禁用化学药品主要是盐酸克仑特罗，但也检出了N，N-二甲基硫脲和甲巯基咪唑，禁用化学药品只在部分区域内检出，因此首要任务是加强对盐酸克仑特罗的监测，同时也要警惕其它禁用化学药品的存在，在对全市的生猪市场进行监测管理时，应着重管理存在问题的地区。     

Tocopherols in coffee brews: Influence of coffee species, roast degree and brewing procedure

Tocopherols in roasted coffee and coffee brews were analysed by HPLC/diode-array/fluorescence detection. Only α and β vitamers were identified in the samples. The influence of several factors on espresso coffee content, as well as on tocopherol extractability, was ascertained, namely, coffee species, roast degree, brew volume and preparation method. Pure arabica espressos contained 2.2 and 3.9 μg of α- and β-tocopherol, respectively, while robusta espressos showed significantly lower amounts (p < 0.05): 1.3 and 1.1 μg, correspondingly. Total contents (α + β) in espressos prepared from commercial blends ranged from 2.2 to 4.8 μg. Overall, tocopherol amounts in the brews corresponded to only 1% of those found in the coffee cake. However, espressos prepared from servings contained ～5-fold higher amounts of tocopherol than those prepared by the classic method. The medium-roast degree seems to be more favourable for the extraction of compounds than light or dark roasts. Compared with other coffee beverages, an arabica espresso cup contained an intermediate level of total tocopherols: 7.0 μg/30 mL, against 4.4 μg for filter (150 mL), 13.6 μg for press-pot (60 mL), 19.7 μg for moka (60 mL), 25.4 μg for Turkish, and 40.1 μg for boiled (150 mL) coffees.     

凝胶渗透色谱和固相萃取净化气相色谱-质谱法检测动物性食品中26种有机氯农药残留

目的:建立一种测定动物性食品中有机氯类多种农药残留的气相色谱质谱分析方法。方法:采用丙酮和正己烷提取肉中多种有机氯类农药,以凝胶渗透色谱(GPC)和固相萃取(SPE)净化、浓缩后,用气相色谱—质谱选择离子监测方式分析检测26种有机氯农药残留。结果:所有26种农药均在20 min内流出,分离良好,农药标准的线性范围在0.01 mg/L～0.5 mg/L相关系数r均在0.99以上,低、高两种浓度加标回收率均在61%～95%之间,相对标准偏差均小于13%,方法最低检出限在0.002 mg/kg～0.005 mg/kg。结论:本方法适合动物性食品中有机氯类农药残留的测定。     

Simple and Sensitive Determination of 2,4-Xylenol in Surface Water Samples from River and Sea by Gas Chromatography–Mass Spectrometry

A simple and selective method was developed for determination of the concentration of 2,4-xylenol in river and sea water samples using gas chromatography/mass spectrometry (GC/MS). Trace amounts of 2,4-xylenol were collected in a Oasis HLB Plus cartridge, eluted with acetonitrile. The method detection limit of 2,4-xylenol was 1.4 ng/L. The trace peaks of 2,4-xylenol were found in water samples from the river and the sea, and the concentrations were all less than 1.4 ng/L. The nine peaks of the 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-xylenol, and o-, m-, p-ethyl phenol that gave the same m/z ratio were separated efficiently.     

Influence of pro- and prebiotics on gastric,duodenal and colonic bioaccessibility of the mycotoxin beauvericin

Beauvericin (BEA) is a bioactive compound produced by the secondary metabolism of several Fusarium strains and known to have various biological activities. This study investigates the influence of several dietary fibers (galactomanan, glucomannan, citrus fiber, bamboo fiber, carrot fiber, pie fiber, β-glucan, xilan, and cellulose) and probiotic strains (Lactobacillus animalis, Lb. casei, Lb. casei, Lb. plantarum, Lb. rhuminis, Lb. casei casei, Bifidobacterium breve, Bf. Adolescents, Bf. bifidum, Corynebacterium vitaeruminis, Streptococcus faecalis, Eubacterium crispatus, and Saccharomyces cerevisiae) on the minor Fusarium mycotoxin BEA bioaccessibility employing a model solution. The bioaccessibility was determined using a simulated gastrointestinal digestion that mimics the physiological conditions of the digestive tract until the colonic compartment. The determination of BEA in the intestinal fluids was carried out by liquid chromatography–mass spectrometry detection (LC–MS). The reduction of BEA bioaccessibility in the experiments carried out using the prebiotic compounds ranged from 60 to 80%, whereas in the trials carried out using the probiotic strains the bioaccessibility observed ranged from 30 to 85%. A BEA degradation product produced by colonic fermentation was identified using the technique of LC–MS-LIT.     

PTV-GC/MS测定饮用水中的土臭素

目的:建立大体积进样、程序升温气化、气相色谱质谱联用测定饮用水中的土臭素的分析方法。方法:水中的土臭素用二氯甲烷萃取后大体积进样,程序升温气化、气相色谱质谱分析测定,选择离子定量。结果:在0~1000 ng/L浓度范围内线性良好,相关系数为0.999,方法检测限为2 ng/L,加标回收率在89%~97%之间,精密度RSD<10%。结论:该方法灵敏度高、准确度好,满足生活饮用水中的土臭素的卫生检测要求。     

Isotope dilution-liquid chromatography/mass spectrometric method for the determination of riboflavin content in multivitamin tablets and infant formula

Isotope dilution liquid chromatography/mass spectrometry (ID-LC/MS) was developed to measure riboflavin contents in infant formula and multivitamin tablets. ¹³C₄, ¹⁵N₂-riboflavin was used as an internal standard. For infant formula, acid hydrolysis was conducted after spiking internal standard to release bound riboflavin. Free riboflavin in the multivitamin tablets was extracted with distilled water for 3 h at 4 °C. The mass spectrometer was operated in selected ion monitoring mode to observe the collisionally induced dissociation channels of m/z 377 → 243 for riboflavin and m/z 383 → 249 for¹³C₄,¹⁵N₂-riboflavin. The developed method was validated based on tests of repeatability and reproducibility, evaluation of measurement uncertainty, and analysis of available certified reference materials. For infant formula and multivitamin samples, the repeatability was 0.1–0.4% and 0.3–1.2%, and the reproducibility was 1.4 and 1.0%, respectively. The realtive expanded uncertainty of analyzing homogenized sample was ranging 1–4%. Therefore, the developed method showed that it has as a high-order metrological quality. The developed ID-LC/MS method was also tested for the accurate analysis of riboflavin in commercial food products including infant formula, breakfast cereals, milk, and multivitamin tablets.     

Spanish smoked meat products: Benzo(a)pyrene (BaP) contamination and moisture

Traditional direct smoking is used for drying and flavouring foodstuffs, although carcinogenic compounds are added during this process, namely polycyclic aromatic hydrocarbons (PAH). The maximum permissible content of benzo(a)pyrene (BaP) (a current marker for the occurrence and effect of PAH in foods) in smoked meat products was reduced from 5 to 2 μg/kg on 1/09/2014, in compliance with European Regulation No. 835/2011. In this study, an analytical method has been developed to determine BaP content consisting of PAH extraction assisted by sonication followed by solid-phase extraction sample clean-up and analytical determination using gas chromatography/mass spectrometry. Sixteen commercial chorizo samples from 16 different Spanish producers from the Principality of Asturias were studied. Five of the samples exceeded the 2 ppb BaP limit. The relationship between moisture and BaP content in chorizo was examined, in order to verify the quality of the manufacturing process. Moisture content did not correlate with BaP content in chorizo.     

Systemic and non-systemic pesticides in apples from Kazakhstan and their impact on human health

Understanding the behavior of pesticides used during fruit cultivation is important for effectively and safety applying to minimize the risk exposure of consumer. The aim of this study was estimated the level of pesticide in 80 apple samples collected from the South Kazakhstan. Additionally, the peel and pulp was investigated. Around 50% samples contained 24 pesticides, ranging 0.006–0.62, 0.005–0.46 and 0.02–1.38 mg/kg in whole apples, pulp and peel, respectively. The penetration factor pesticide peel/pulp was calculated and ranged 1.7–10.9 for kresoxim methyl and triazophos, respectively. Acute (aHI) and cumulative (cHQ) exposure health risks associated with consuming these pesticides in whole fruit, pulp and skin were estimated. The triazophos, chlorpiryfos and cyhalothrin exceeded safety ARfD: 830, 136 and 112% for adults, whereas for infants 4514, 742 and 609%. The cHQ exposure were the highest in peel for AChE inhibitors: 999%, and sodium channel modulators 123% for adults.     

Identification of potential bioactive peptides generated by simulated gastrointestinal digestion of soybean seeds and soy milk proteins

In this work, the bioactive peptides produced during in vitro gastrointestinal digestion of soybean seeds and soy milk were investigated. The analysis was performed on extracted protein samples from soybean seeds and milk or directly on untreated soy milk. Proteins samples were subjected to simulated gastrointestinal digestion and then analyzed by nano-liquid chromatography coupled to tandem mass spectrometry for peptide sequencing. The identified peptides were 1173 in soybean seed samples, 1364 in untreated soy milk samples and 1422 in soy milk samples in which proteins were extracted by precipitation. The peptide identifications were then employed to search specific databases and look for the presence of bioactive peptides in the investigated samples, either with known biological activity or with potential antimicrobial activity. Results pointed out that soybean proteins underwent an extensive degradation process during gastrointestinal digestion and generated a large number of bioactive peptides, some with established activity, some with predicted antimicrobial activity. Finally, the supernatants collected after protein precipitation with acetone from both soybean seeds and soy milk were also analyzed to evaluate the presence of peptides produced by the action of endogenous proteases. Likely, peptides found in soy milk samples could be formed during food processing.     

代谢综合征患者血清游离脂肪酸成分特征的研究

目的研究代谢综合征（MS）及高危患者血清游离脂肪酸（FFA）成分特征及与其他糖脂代谢参数间关系.方法用气相色谱-质谱（GC-MS）联用法测定159名MS及MS高危患者与43例正常对照者血清游离脂肪酸成分水平.结果MS患者不饱和脂肪酸（C18：2、C18：1、C20：4、C22：6、C20：3）高于正常对照组,C18：2、C20：3有统计学意义（P＜0.01）;不饱和脂肪酸/总脂肪酸（UFA/TFA）、多不饱和脂肪酸/总脂肪酸（PUFA/TFA）、多不饱和脂肪酸/饱和脂肪酸（PUFA/SFA）高于正常对照组（P＜0.01）;SFA（C16：0、C18：0）和SFA/TFA低于正常对照组（P＜0.01）.MS组与MS高危组相比,FFA各指标无统计学意义（P＞0.05）.研究对象血糖与UFA/TFA、PUFA/TFA、PUFA/SFA呈显著正相关（r=0.229,0.204,0.230,P＜0.01）,血糖与SFA/TFA呈显著负相关（r=-0.229,P＜0.01）.结论MS及MS高危患者中存在游离脂肪酸代谢紊乱.n6系多不饱和脂肪酸升高,可能在MS发病中起重要作用.     

Use of Quick,Easy, Cheap,Effective, Rugged & Safe (QuEChERS) and molecular imprinted polymer followed by gas chromatography with tandem mass spectrometry for the quantitative analysis of polycyclic aromatic hydrocarbons (PAH4) in complex health supplements

A gas chromatography-tandem mass spectrometry sensitive and selective method based on a combination of QuEChERS and subsequent molecularly imprinted polymer (MIP) technology was validated for the analysis of polycyclic aromatic hydrocarbons in complex dry extracts of Eleutherococcus senticosus, Salvia officinalis, Camellia sinensis, Zingiber officinale, Uncaria tomentosa, Humulus lupulus, Pinus sylvestris L., Spirulina maxima, propolis and royal jelly. The method has been optimized using gas chromatography coupled to tandem mass spectrometry. An additional sample treatment of the dry extracts, based on the combined use of MIP-SPE and QuEChERS, was required because of the strong matrix effect observed related to interferences affecting analyte quantification. Estimation of the method detection limit and quantification limit was carried out for validation. The LOQs were 0.2 ng g⁻¹ for benz[a]anthracene, 0.3 ng g⁻¹ for benzo[a]pyrene and 0.4 ng g⁻¹ for benzo[b]fluoranthene and chrysene; and the LODs were 0.07, 0.09 and 0.1 ng g⁻¹ respectively. Recoveries were in the range of 88.5 % for B[b]F, to 114 % for B[a]A, and % RSD was < 14 % in all cases. The method was applied in routine analysis to a wide variety of dry extracts from EU and non-EU manufacturers.     

Identification and quantification of polyphenolic compounds in ten pear cultivars by UPLC-PDA-Q/TOF-MS

The aim of this study was to identify and compare phenolic acids, flavan-3-ols and procyanidins, flavonol glycosides, flavones and hydroquinones in different cultivars of pear. Pear fruits (Pyrus communis L.) of ten cultivars (‘Bonkreta Williamsa’, ‘Carola’, ‘Dicolor’, ‘Faworytka’, ‘Hortensia’, ‘Konferencja’, ‘Lukasówka’, ‘Nojabrska’, ‘Radana’ and ‘Uta’) were used in this study. Sixty-five phenolic compounds, including 26 phenolic acids, 22 flavan-3-ols and procyanidins, 15 flavonols, 1 flavone, and 1 hydroquinone, were determined in the examined samples using the ultra-performance liquid chromatography photodiode detector-quadrupole/time of flight-mass spectrometry (UPLC-PDA-Q/TOF-MS) method. Major differences were found in the phenolic profiles of investigated cultivars. The ‘Radana’ cultivar exhibited the highest total phenolics content (894.9 mg/kg FW) and was characterized by the highest concentration of phenolic acids (503.1 mg/kg FW) and arbutin (70.8 mg/kg FW).     

An evaluation of volatile compounds released from containers commonly used in circulation of sports beverages

In an effort to identify and quantify important volatile organic compounds (VOCs) released from sports beverage containers commonly used for storage and distribution, three brands of sports beverages with poly ethylene terephthalate (PET) and metal cans were analyzed through headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Out of 80 volatile compounds identified from all container types, I-limonene recorded the highest concentration (34.3-118 pmol mol⁻¹) along with 12 other VOCs detected most frequently (more than 3 out of all 6 products) such as 2-methyl-6-methylene-2,7-octadiene, alpha-terpineol, decanaldehyde, and p-isopropyltoluene. When each container was filled up with water and analyzed after a long-term storage (49 days), a total of 14 VOCs were detected. According to our analysis, all the VOCs detected from either beverage or container materials were below the safety limits prescribed previously by diverse agencies. However, an extension of these analyses may be necessary for other beverage types, as certain VOCs can be migrated from container materials.     

吹扫捕集气相色谱质谱法测定饮用水中挥发性有机物

目的建立吹扫捕集气相色谱质谱联用测定饮用水中挥发性有机物的分析方法。方法采用吹扫捕集富集水中挥发性有机物,解吸后用GC/MS测定,选用特征离子定量。结果在36分钟内60种VOCs有效分离,在0μg/L~12μg/L浓度范围内,51种目标化合物的相关系数大于0·995,方法检测限范围为0·021μg/L~0·70μg/L,样品加标回收率在90%~120%之间,响应因子的相对标准偏差小于30%。结论该方法灵敏度高、准确度好,适合于饮用水中挥发性有机物的分析测定。