So far, there has been no quality evaluation of Tricholoma matsutake. Nucleic acid compounds are a kind of functional ingredient in T. matsutake that is beneficial to human health. In this study, a UPLC-TOF/MS method was first used to scan and identify the potential nucleic acid compounds in T. matsutake. Based on the calculation of the molecular formula and subsequent confirmation by authentic standards, 15 nucleic acid compounds were unambiguously identified: adenosine, cytidine, guanosine, inosine, thymidine, uridine, xanthosine dehydrate, 2′-deoxyadenosine, 2′-deoxycytidine, 2′-deoxyguanosine, 2′-deoxyuridine, adenosine 5′-monophosphate, cytidine 5′-monophosphate, guanosine 5′-monophosphate, and uridine 5′-monophosphate. Then, a UPLC-QqQ/MS method was developed for the subsequent quantitative analysis. After validating the limits of quantification, detection, precision, repeatability, and recovery through a calibration curve, the content of 15 nucleic acid compounds was determined by the proposed UPLC-QqQ/MS method in 80 T. matsutake samples collected from different regions in Sichuan province, Southwest China. After the statistical analysis, we suggest that the total content of nucleic acid compounds in the qualified T. matsutake should be higher than 24.49 mg/100 g. The results indicated that the combined use of UPLC-TOF/MS and UPLC-QqQ/MS is efficient for fast identification and determination of nucleic acid compounds to comprehensively evaluate the quality of T. matsutake.

So far, there is no report on the quality evaluation of lemonade available in the market. In this study, a sample preparation method was developed for the determination of flavonoid glycosides by ultra-performance liquid chromatography–mass spectrometry (UPLC-MS) based on vortex-assisted dispersive liquid-liquid microextraction. First, potential flavonoids in lemonade were scanned and identified by ultra-performance liquid chromatography–time of flight mass spectrometry (UPLC-TOF/MS). Five flavonoid glycosides were identified as eriocitrin, narirutin, hesperidin, rutin, and diosmin according to the molecular formula provided by TOF/MS and subsequent confirmation of the authentic standard. Then, an ultra-performance liquid chromatography–triple quadrupole mass spectrometry (UPLC-QqQ/MS) method was developed to determine these five flavonoid glycosides in lemonade. The results showed that the content of rutin in some lemonade was unreasonably high. We suspected that many illegal manufacturers achieved the goal of low-cost counterfeiting lemonade by adding rutin. This suggested that it was necessary for relevant departments of the state to make stricter regulations on the quality standards of lemonade beverages.

No abstract

In the present study, 11 non-anthocyanin polyphenols, gallic acid, protocatechuate, vanillic acid, syringic acid, ferulic acid, quercetin, catechin, epicatechin, epigallocatechin gallate, gallocatechin gallate and epicatechin gallate—were firstly screened and identified from blueberries using an ultra performance liquid chromatography–time of flight mass spectrography (UPLC-TOF/MS) method. Then, a sample preparation method was developed based on vortex-assisted dispersive liquid-liquid microextraction. The microextraction conditions, including the amount of ethyl acetate, the amount of acetonitrile and the solution pH, were optimized through the multi-objective response surface methodology and desirability function approach. Finally, an ultra performance liquid chromatography–triple quadrupole mass spectrography (UPLC-QqQ/MS) method was developed to determine the 11 non-anthocyanin polyphenols in 25 commercial blueberry samples from Sichuan province and Chongqing city. The results show that this new method with high accuracy, good precision and simple operation characteristics, can be used to determine non-anthocyanin polyphenols in blueberries and is expected to be used in the analysis of other fruits and vegetables.

A novel flow injection chemiluminescence method for the determination of orciprenaline was developed. The method is based on the chemiluminescence (CL) reaction of orciprenaline with potassium ferricyanide in sodium hydroxide medium, sensitized by the fluorescent dye rhodamine 6G. The proposed procedure allows quantitation of orciprenaline in the concentration range 0.01-1.2 microg/mL, with a detection limit of 7.2 x 10(-3) microg/mL. The relative standard deviation (RSD) is 2.7% for 0.1 microg/mL orciprenaline (n = 9). The sampling frequency was calculated at approximately 120/h. The method was successfully applied to the determination of orciprenaline in pharmaceutical preparations. A brief discussion on the possible CL reaction mechanism is presented.