Adulterants in Whiskey: Detection and Identification by Principal Component Analysis

Model adulterants such as gasoline, phenol, rubber hose, and hair were added to whiskies to prepare adulterated samples. Methylene chloride extracts of these and of the unadulterated whiskies were separated by capillary column GC. Principal Component Analysis was applied to the gas chromatograms, and the resulting scores were used to decide upon product acceptability. Using a series of standards, scores were also the basis for identification of adulterants in rejected samples. In the largest of three data sets, decisions were correct for over 95% of samples, and all adulterated samples were correctly identified.     

Rapid screening for the adulterants of Berberis aristata using direct analysis in real-time mass spectrometry and principal component analysis for discrimination

Adulteration or substitution of commercial Berberis aristata and its herbal products with inferior-quality substituents is very common. Metabolic profiling of B. aristata, along with its common adulterants/contaminants/substituents such as B. asiatica, Mahonia borealis and Coscinium fenestratum, was rapidly carried out using direct analysis in real-time mass spectrometry (DART MS) to generate the chemical fingerprints for the differentiation of these species. Phytochemical analysis showed the presence of mainly alkaloids. The identified alkaloids were berberrubine, berberine, jatrorrhizine, ketoberberine, palmatine, dihydropalmatine or 7,8-dihydro-8-hydroxyberberine, berbamine and pakistanamine. Berberine, which was mainly reported from the root and stem bark of B. aristata, was also identified in the leaf along with chlorogenic acid. The DART MS data have been subjected to principal component analysis (PCA). The resulting score plots showed clustering and clear differentiation of the species and plant parts. It is thus apparent that the technique of DART MS followed by PCA is a quick and reliable method for the direct profiling of B. aristata and its adulterant plants and plant parts. The study reports the rapid analytical method to identify the possibility of illegal adulteration/contamination/substitution in potential plant materials and herbal extracts.     

Applications of Raman spectroscopic techniques for quality and safety evaluation of milk: A review of recent developments

Milk is a complete nutrient source for humans. The quality and safety of milk are critical for both producers and consumers, thereby the dairy industry requires rapid and nondestructive methods to ensure milk quality and safety. However, conventional methods are time-consuming and laborious, and require complicated preparation procedures. Therefore, the exploration of new milk analytical methods is essential. This current review introduces the principles of Raman spectroscopy and presents recent advances since 2012 of Raman spectroscopic techniques mainly involving surface-enhanced Raman spectroscopy (SERS), fourier-transform (FT) Raman spectroscopy, near-infrared (NIR) Raman spectroscopy, and micro-Raman spectroscopy for milk analysis including milk compositions, microorganisms and antibiotic residues in milk, as well as milk adulterants. Additionally, some challenges and future outlooks are proposed. The current review shows that Raman spectroscopic techniques have the promising potential for providing rapid and nondestructive detection of milk parameters. However, the application of Raman spectroscopy on milk analysis is not common yet since some limitations of Raman spectroscopy need to be overcome before making it a routine tool for the dairy industry.     

Detection of hazardous weight-loss substances in adulterated slimming formulations using ultra-high-pressure liquid chromatography with diode-array detection

The presence on the market of illegal products for slimming purposes or the treatment of overweight is a public health issue. These products may contain illicit chemicals in order to improve their effectiveness. Some of these weight-loss compounds are responsible for adverse events, including fatal outcomes. A general strategy for the analysis of any suspect formulation begins with a large screening for the general search of a wide range of compounds. A methodology for the qualitative and quantitative determination of 34 compounds in slimming preparations (such as dietary supplements or medicinal products) was used for the control of slimming formulations from the market, including over the Internet. The fast liquid chromatography system (ultra-high-pressure liquid chromatography) used a gradient of solvent (phosphate buffer and acetonitrile), a C18 endcapped column and a diode array detector. This system allows dual identification based on retention time and UV spectra. The analytical method is simple, fast and selective since 34 weight-loss compounds can be detected in a 15-min run time. Thus, 32 commercial slimming formulations were analysed using this method, allowing the detection and quantification of hazardous active substances: caffeine, clenbuterol, nicotinamide, phenolphthalein, rimonabant, sibutramine, didesmethylsibutramine, synephrine and yohimbine.     

Development and validation of an LC-MS/MS method for the simultaneous analysis of 28 specific narcotic adulterants used in dietary supplements

The purpose of this study was to develop a method to analyse the concentration of multiple illegal narcotics present in dietary supplements. To this end, we established and optimised a procedure using LC-MS/MS simultaneously to analyse 28 narcotic compounds in various forms of dietary supplements, including powders, tablets, liquids and capsules. In addition, candy and cookies that have also had detected cases of adulteration were also analysed. The specificity, linearity, accuracy, precision, limit of detection (LOD), limit of quantitation (LOQ), stability and recovery for these methods were validated accordingly. The LOD and LOQ of the LC-MS/MS ranged from 0.01–50.0 to 0.03–100 ng g^?1, respectively. The linearity of these results was good (r² > 0.99), with intra- and inter-day precision values of 0.2–5.2% and 0.2–4.8%, respectively. Further, the intra- and inter-day accuracies of this method were 97.0–103.4% and 94.6–103.1%, respectively. The stability RSD was less than 7.8%. The mean recovery for this LC-MS/MS procedure was 81.1–117.4%, with an RSD less than 9.8%. Following the validation of our method, we analysed 47 commercially available dietary supplements obtained in Korea. Whilst none of these samples had detectable amounts of the 28 specified narcotic adulterants, our novel LC-MS/MS procedure can be utilised comprehensively and continually to monitor illegal drug adulteration in various forms of dietary supplements.     

Determination of diuretics and laxatives as adulterants in herbal formulations for weight loss

A new method is described for the determination of the most common diuretic and laxative adulterants found in formulations of anorexics and antidepressants. The method is based on the separation of furosemide, hydrochlorothiazide, chlorthalidone and amiloride (diuretics), phenolphthalein (laxative), amfepramone (anorexic) and fluoxetine and paroxetine (antidepressants) by capillary zone electrophoresis with capacitively coupled contactless conductivity detection. The method showed a precision ranging from 1.9% to 6.9% for a concentration of 25 mg/L, 0.6% to 5.3% for a concentration of 50 mg/L and 1.6% to 6.0% for a concentration of 100 mg/L for all analytes. The accuracy was 99% for amiloride, 102% for chlorthalidone, 101% for hydrochlorothiazide, 101% for furosemide, 94% for phenolphthalein, 105% for fluoxetine, 114% for paroxetine and 117% for amfepramone. The method allowed the drugs to be determined in the formulations at concentrations higher than 5.1 mg/kg for amiloride, 7.7 mg/kg for chlorthalidone, 6.8 mg/kg for hydrochlorothiazide, 10.7 mg/kg for furosemide, 8.4 mg/kg for phenolphthalein, 11.0 mg/kg for fluoxetine, 9.4 mg/kg for paroxetine and 11.0 mg/kg for amfepramone. Three of the 26 analysed herbal formulations were found to be adulterated (not declared on the label) with the diuretic hydrochlorothiazide. Five other samples contained diuretics declared on the label on the formulation. Thus, a total of eight samples, which were marketed as natural products, contained diuretics (declared or not) on the formulation.     

基于卷积神经网络的乳粉掺杂物拉曼光谱分类方法

提出一种基于卷积神经网络的乳粉掺杂物拉曼光谱分类方法。首先利用拉曼高光谱成像平台采集足量乳粉样品的原始光谱,然后利用离散小波变换对原始光谱进行预处理,将预处理后的光谱信号作为卷积神经网络输入构建模型,并分别比较光谱预处理前后的建模效果。结果表明,不合适的光谱预处理反而会降低卷积神经网络的分类效果,而原始拉曼光谱就能被卷积神经网络精准识别,所构建的原始光谱模型对实际未知样品的识别准确率为95.5%。结果表明,卷积神经网络具备光谱预处理与建模的一体化功能,可极大简化拉曼光谱分类识别的计算过程,对乳粉质量安全筛查具有重要意义。     

八角茴香真伪鉴别研究进展

八角茴香作为“药食同源”调味品和中药材,在人们日常生活中应用广泛且价格较高。在巨大的市场需求与利益面前,经常出现使用莽草、红茴香、野八角、日本八角等木兰科植物果实冒充八角茴香进行销售和使用的现象,从而影响到人民群众身体健康和生命安全,八角茴香掺假在全球范围内已成为普遍存在的现象和问题。为了保障消费者合法权益以及人们的用药和饮食安全,本文在对八角茴香及其常见混伪品进行介绍的基础上,着重介绍了八角茴香及其伪品的性状、显微、理化、光谱分析、色谱分析、机器视觉分析、气味指纹分析等不同鉴别方法,并展望了八角茴香真伪鉴别检测的发展方向和相关检测技术的应用前景,以期为八角茴香及其掺伪品的精准鉴别提供参考。     

Food adulteration: Sources,health risks,and detection methods

Adulteration in food has been a concern since the beginning of civilization, as it not only decreases the quality of food products but also results in a number of ill effects on health. Authentic testing of food and adulterant detection of various food products is required for value assessment and to assure consumer protection against fraudulent activities. Through this review we intend to compile different types of adulterations made in different food items, the health risks imposed by these adulterants and detection methods available for them. Concerns about food safety and regulation have ensured the development of various techniques like physical, biochemical/immunological and molecular techniques, for adulterant detection in food. Molecular methods are more preferable when it comes to detection of biological adulterants in food, although physical and biochemical techniques are preferable for detection of other adulterants in food.     

表面增强拉曼光谱在食品污染物快速检测中的应用

随着科技的发展,食品的种类越来越丰富,随之而来的问题是食品中引入的污染物也越来越复杂,这使得食品安全成为当今全球关注的一个重要话题,快速有效地检测食品中污染物已然成为食品检测的热点。表面增强拉曼光谱(surface-enhanced Raman spectroscopy, SERS)由于其极高的灵敏度、快速检测、指纹图谱解释能力,以及高达单分子级别的检测水平,逐渐成为检测食品中污染物的常用方法。本文针对SERS基底的发展现状,如特殊形态金属纳米颗粒和固相SERS平台,以及SERS在农兽药,掺假,天然毒素以及食源性病原体等污染物中的检测方法进行了论述,以期为表面增强拉曼光谱未来在食品污染物快速检测中的应用提供参考。