Detection Of Multiple Components Research Articles

Simultaneous analysis of natural and artificial sweeteners in sugar-free drinks and urine samples by column-switching UHPLC-charged aerosol detection method

Sweeteners are considered an alternative to high-calorie foods or drinks and have been widely used globally. However, the simultaneous separation and detection of high-polarity natural and artificial sweeteners are challenging owing to their broad-spectrum physical and chemical properties. Herein, we developed a column-switching UHPLCCAD method and used it for detecting and quantitating 12 sweeteners, including natural sweeteners (erythritol, mannitol, xylitol, sorbitol and stevioside) and artificial sweeteners (acesulfame potassium, saccharin sodium salt, sodium cyclamate, sucralose, aspartame, alitame and neotame). The LOD and LOQ were 0.932–6.25 μg/mL and 3.10–20.83 μg/mL, respectively, and the method demonstrated excellent linearity (R² ≥ 0.9990), good precision (intraday and interday precision was 0.59–6.88 %), and high recovery (average recoveries were 85.16–108.64 %). This method was applied to determine the sweeteners in 15 sugar-free drinks purchased from the local Chinese supermarkets. What's more, natural sweetener erythritol and artificial sweetener acesulfame potassium were suspected over addition in sugar-free drinks. Meanwhile the method was applied to the sweeteners in various sugar-free drinks and the dynamic monitoring of transit and excretion in vivo after drinking. Those prove that the method can be used to the detection of sugar free drinks and quality control of the sweeteners. The study highlights the potential of UHPLC–charged aerosol detection technology in detection of multiple components in food industry.

Combined Paper Centrifugal Chromatographic Separation and SERS Detection for Multicomponent Substances.

The separation and chemical analysis of mixtures in an emergency situation represent major challenges, especially in remote or poverty-stricken areas. A novel method was developed for the rapid separation and detection of multiple components via paper centrifugal chromatography, which costs as little as $2.26 US. The method was realized based on the combination of portable paper centrifugal chromatography and surface-enhanced Raman scattering (SERS) detection. This coupled technique was successfully implemented for the separation and qualitative analysis of a rhodamine 6G-crystal violet mixture and a colorless aniline-pyrocatechol-benzidine mixture. A chromatographic mobile phase was collected using absorbent cotton, which was demonstrated to have no effect on the SERS results. The optimized device achieved rapid and effective separation of the colorless aniline-pyrocatechol-benzidine mixture with a high centrifugal force (0.3303π2 N). The newly developed method involving multicomponent paper centrifugal chromatography-SERS detection will be of great value for emergency-related substance separation and analysis in remote and poor areas.

Abstract 4319: Analysis of Bcl-2 family members and protein-protein interactions using novel multiplex immunoassays

Abstract Bcl-2 family members play a very important role in intrinsic apoptotic pathways. The family consists of more than 17 members that can be functionally separated into pro-apoptotic and anti-apoptotic subfamilies. Interactions between these family members determine cell fate, and dysregulation can lead to tumor growth and tumor cell survival. There are several investigational drugs for cancer treatment targeting Bcl-2 family members in clinical trials, driving the need for robust assays to measure Bcl-2 family members and their interactions. Though existing assays measure Bcl-2 family members, there is a lack of reliable assays to evaluate total proteins and protein-protein interactions simultaneously. To address this issue, we have developed two Luminex®-based multiplex immunoassay panels that allow for the simultaneous detection of multiple components of the Bcl-2 family in a single well, including Total Bcl-2, Bcl-xL, Mcl-1, BAD, BIM, and BAX as well as protein interactions like NOXA/Mcl-1, Mcl-1/BIM, and Bcl-xL/BAD. Using these panels, we analyzed changes in the expression and interactions of Bcl-2 family members in response to known apoptotic drugs, including Camptothecin (topoisomerase inhibitor), Anisomycin (protein translation inhibitor), and AT101 (BH3 mimetic drug). Camptothecin and Anisomycin each elicited a significant decrease in the levels of Mcl-1. Additionally, the Mcl-1/BIM interaction was disrupted by both Camptothecin and Anisomycin, perhaps a consequence of the reduced Mcl-1 levels. However, expression of the other anti-apoptotic proteins was unaffected by any of the three drugs. Interestingly, all three treatments had different effects on the Mcl-1/NOXA interaction. Mcl-1/NOXA signal was increased by AT101, decreased by Anisomycin, and showed a dose dependent effect with Camptothecin. In contrast to their disparate effects on the Mcl-1/NOXA interaction, all three drugs acted in a similar manner in blocking the Bcl-xL/BAD interaction without affecting the total levels of either protein. Overall, these results illustrate the dynamic responses of the Bcl-2 family to apoptosis-inducing drugs. The novel multiplex immunoassays described here provide a powerful tool for studying the underlying mechanisms regulating the Bcl-2 family of proteins. Citation Format: Reeti Maheshwari, Melissa Schluter, Danielle Pepin, Joseph Hwang. Analysis of Bcl-2 family members and protein-protein interactions using novel multiplex immunoassays [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4319. doi:10.1158/1538-7445.AM2017-4319

Analysis of Individual Signaling Complexes by mMAPS, a Flow-Proteometric System.

Signal transduction is essential for maintaining normal cell physiological functions, and deregulation of signaling can lead to diseases such as diabetes and cancers. Some of the major players in signal delivery are molecular complexes composed of proteins and nucleic acids. This unit describes a technique called microchannel for multiparameter analysis of proteins in a single complex (mMAPS) for analyzing and quantifying individual target signaling complexes. mMAPS is a flow-proteometric system that allows detection of individual proteins or complexes flowing through a microfluidic channel. Specific target proteins and nucleic acids labeled by fluorescent tags are harvested from tissues or cultured cells for analysis by the mMAPS system. Overall, mMAPS enables both detection of multiple components within a single complex and direct quantification of different populations of molecular complexes in one setting in a short timeframe and requiring very low sample input.

Development of a Hand-Held near Infrared System Based on an Android OS and MicroNIR, and its Application in Measuring Soluble Solids Content in Fuji Apples

Near infrared (NIR) spectroscopy has been widely applied in the areas of agriculture, food, pharmaceutical and chemical industries because of its advantages such as its speed, non-destructive nature and simultaneous detection of multiple components. However, most existing NIR instruments are too large to be carried into the field. Herein, we have developed an interface by which the application (app) runs on a smart phone (or tablet) to drive a miniature NIR spectrometer (MicroNIR, a product of the JDSU Uniphase Corporation). This app has three modules; the first drives the hardware to control the spectrometer; the second facilitates graphical display of spectral data, spectral pretreatment according to method provided by the model file and production of a calculated result while the third is the management of models, samples, spectral parameter setting and an address book. We have used this app with the MicroNIR to measure soluble solids content (SSC) in Fuji apples in the field; results were compatible with the reference results based on an Abbé refractometer analysis. To conclude, this new hand-held NIR spectroscopy system based on android device is convenient and practical in rapid measurement of SSC of Fuji apples in the field. It has potential to be used for in situ measurement of other constituents of agriculture products.

5436562 Methods for the simultaneous detection of multiple components of motion in moving fluids

5436562 Methods for the simultaneous detection of multiple components of motion in moving fluids