Analysis of Amino Acid and Phenolic Content in Honey by UPLC-ESI-MS/MS

Honey is the very valuable natural animal product. It offers more than hundred nutritional substances to its consumers, human being and animals. Though major constituent of honey is sugar and water, honey also possesses amino acids, phenolic compounds, vitamins, minerals and enzymes. Amino acids are one of the important components of food. They provide the required building blocks and protein synthesis. Moreover, phenolic compounds in honey constitute the important quality parameter and account for its colour, sensory properties and antioxidant activity. Analysis of phenolic compound and amino acid is very important. They are generally used to identify the origin of honey. Amino acids in honey come from animals and vegetables. In the literature, there are several techniques concerning amino acid and phenolic compound identifications. In this chapter, usage of ultra-performance liquid chromatography with electrospray ionization coupled to tandem mass spectrometry (UPLC-ESI-MS/MS) techniques and methods for the determination of amino acids and phenolic compounds of honey is explained

Analytical evaluation of phenolic compounds and minerals of Opuntia robusta J.C. Wendl. and Opuntia ficus-barbarica A. Berger

In this study, 19 phenolic compounds were detected using high-throughput instrument ultra performance liquid chromatography with electrospray ionization tandem mass spectrometry (UPLC–ESI–MS/MS) in Opuntia ficus-barbarica A. Berger and Opuntia robusta J.C. Wendl. fruits. The five macro- and five micro-minerals determined in both species were analyzed using inductively coupled plasma–mass spectrometer. The phenolic compounds, mineral content, and the antioxidant capacity of the fruits of O. robusta and O. ficus-barbarica were analyzed. All phenolic compounds and minerals varied significantly between the two species. The total of phenolic compounds content was calculated as 69.237 and 66.385 mg kg−1, respectively, in O. ficus-barbarica and O. robusta. Ferulic acid was the highest quantities, 31.620 and 26.931 mg kg−1 in O. robusta and O. ficus-barbarica, in all phenolic contents, respectively. The macroelements calcium and potassium were the most abundant in both Opuntia species. The antioxidant activity of O. ficus-barbarica and O. robusta fruit samples was measured in the extracts of hexane, ethyl acetate, methanol, and water. The DPPH assay of Opuntia samples displayed a good radical scavenging inhibition, similar to butylated hydroxyanisole and butylated hydroxytoluene standards, as half maximal inhibitory concentration IC50 = 69.32 and 67.57 μg mL−1 in ethyl acetate extracts of O. ficus-barbarica and O. robusta fruits, respectively. This work presents a suitable method for the extraction, detection, and quantification of phenolic compounds by UPLC–ESI–MS/MS. MS/MS determination for multiclass determination was validated in Opuntia samples obtaining good results. Abbreviations: ABTS, 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid; AChE, acetylcholinesterase; BChE, butyrylcholinesterase; BHA, butylated hydroxyanisole; BHT, butylated hydroxytoluene; DPPH, 2,2-diphenyl-1-picrylhydrazyl; DTNB, (5,50-Dithio-bis(2-nitrobenzoic)acid; ICP/MS, inductively coupled plasma/mass spectrometer; LoD, yhe limit of detection; MRM, multiple reaction monitoring; QEs, quercetin equivalents; PEs, pyrocatechol equivalents; R2, correlation coefficients; r, Pearson’s correlation coefficient; SD, standard deviation; TIC, total ion chromatogram; UPLC–ESI–MS/MS, ultra performance liquid chromatography with electrospray ionization tandem mass spectrometr

Development and validation of modified QuEChERS method coupled with GC-MS/MS for 123 pesticide residues in food

In this study, a gas chromatography-tandem mass spectrometry (GC-MS/MS) instrument, which has been widely used in recent years and has high separation power, selectivity and ability to identify pesticides has been used. It is aimed that the main criterion of this analytical method, in which the QuEChERS methodology is used, is applicable to fast, easy, cheap, environmentally friendly and different matrices. At the same time with this method, 123 pesticide residues and their degradation products were quantitatively assayed by GC-MS/MS as well as method validations in tomatoe, lemon, lettuce, almonds, raisins, honey, green pepper, milk and flour. Tomatoe was selected as potential reference matrixes for the target. The steps of concentration and solvent exchange were performed in the resultant extracts for the purpose of improving analytical performance in terms of recovery, precision, linearity, of reducing the amount of co-extracts. Multiple reaction monitoring (MRM) was used to identify and quantify the pesticides. The samples were extracted with 1% acetic acid in acetonitrile, anhydrous magnesium acetate, anhydrous magnesium sulfate and clearing agent. For all pesticides, good linear calibrations with coefficients (R2) ≥0.99 for nearly all of the analytes were obtained.  Limit of quantitation of most of the pesticides were in the range of 5-10 ng/g, and recovery of the method validation accuracy parameter was done at two different concentrations 10 ng/g and 50 ng/g were 88.6 - 99.7% and CV 1.60 – 14.0%

Pesticide analysis and method validation with GC/MSD instrument in environmental water samples

Bu çalışmada, su numunelerinde 130'dan fazla pestisit kalıntısının ppb (μg/L) düzeyinde belirlenmesinde kullanılabilecek hızlı ve çoklu bir analiz yöntemi önerilmiştir. Bu amaçla, analit konsantrasyonunun zenginleştirilmesi için bir Kuderna-Danish Evaporatif Konsantratör ve SIM (Selective Ion Monitoring) modunda çalışan gaz kromotografisi (GC) ile birleştirilmiş kütle spektrometresinin (MSD) kullanıldığı bir yöntem geliştirildi ve çoklu pestisit analizi için validasyonu yapıldı. Kromatografik analizde, pestisitlerin düşük konsantrasyonlarda dahi yüksek hassasiyetle tespit edilebilmesi gerektiğinden dolayı 30m HP-5 MS UI kapiler GC kolonu kullanıldı. Geliştirilen yöntemle miktar tayin limitleri 1.8 ve 29.2 ng.L-1 olarak belirlendi. Yöntem, bileşiklerin çoğunda sırasıyla 10 ppb ve 50 ppb seviyeleri için 70.1-116.5 % ve 70.7 – 114.0% aralıklarında ortalama geri kazanım sağladı. Pestisitlerin birbirinden çok farklı kimyasal yapıları, analizi yapılan tüm bileşikler için iyi bir geri kazanım sağlamayı zorlaştırmış olmasına rağmen sonuçların hassasiyetinin mükemmel olduğu değerlendirilebilir. Metodun seçiciliği, hesaplama ve tanımlama iyonlarının bağıl oranı yoluyla değerlendirildi ve değerlendirme sonucunda yeterli kabul edildi. Gerçek numunelerdeki analizler, enstrümantal yeterlilik kriterlerini ve sistem uygunluğu değerlendirmesini karşılamıştır. Böylelikle, 130 pestisitin nitel ve nicel tayinleri yapılmıştır.In this study, a rapid and multiple method has been proposed which can be used in determination of more than 130 pesticide residues at ppb (μg/L) level in water samples. For this purpose, a Kuderna-Danish Evaporative Concentrator, which was used for enrichment of the analyte concentration in the samples and gas chromatography coupled mass spectrometry in the selective ion monitoring (SIM) mode was developed and validated for the multi-class determination of pesticides. In the analysis, a 30m HP-5 MS UI capillary GC columns was used. The high sensitivity of chromatographic analysis was necessary, due to that these pesticides must be determined at low concentrations. The method presented quantification limits between 1.8 and 29.2 ng.L-1 . Most of the compounds presented mean recoveries between 70.1-116.5 % and 70.7 – 114.0% at 10 ppb and 50 ppb levels, respectively. Although the difference in chemical natures of the pesticides made difficult to attain good recovery for all of the compounds evaluated, the precision of the results was excellent. The selectivity of the method was evaluated through the relative intensity of quantification and qualification ions and was considered adequate. Analysis in real samples met criteria for instrumental qualification and the system suitability evaluation. Thus, qualitative and quantitative determinations of 130 pesticide were done

Boronic acid functionalized silica microparticles for isolation of flavonoids from Hypericum perforatum

We have selectively separated cis- and/or vicinal-diol-containing flavonoids from Hypericum perfaratum (HP) by adsorption/desorption using aminophenylboronic acid (APBA) functionalized uniform (1.6 μm) silica microparticles (BASPs) synthesized via the Stöber method. Silica particles were alkylated by its terminal –OH with 3-aminopropyl trimethoxysilane (APTS), glutaraldehyde (GA) and APBA. The results from model adsorption studies indicated that these microparticles selectively adsorbed quercetin and rutin but partially apigenin. The antioxidant and antiradical activities of the desorption solution were slightly higher than that of the post-adsorption solution. These results indicated that the BASP selectively adsorbed the cis- and/or vicinal antioxidant and antiradical flavonoids