Determination of tocopherols and tocotrienols in cereals by pressurized liquid extraction–liquid chromatography–mass spectrometry

Bustamante-Rangel, Myriam; Delgado-Zamarreño, M.M.; Sánchez-Pérez, A.; Carabias‐Martínez, Rita

doi:10.1016/j.aca.2007.01.049

Cited by 73 publications

(40 citation statements)

References 28 publications

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“…Ionization to the negative pseudo‐molecular ion ([M − H] − ) was chosen for detection of the analytes because it provides more stable ions than ionization to the positive pseudo‐molecular ion ([M + H] + ), even for the Ts, which have traditionally been measured as positive ions (Lanina et al ., ; Bustamante‐Rangel et al ., ). Accordingly, ionization in the ESI source rendered m / z values of 205, 263, 401, 415 and 429 for LA, TME, δ ‐T, γ ‐T and α ‐T, respectively.…”

Section: Resultsmentioning

confidence: 99%

Determination of lipoic acid, Trolox methyl ether and tocopherols in human plasma by liquid‐chromatography and ion‐trap tandem mass spectrometry

Montero

Ramírez

Sánchez‐Guijo

et al. 2012

Biomedical Chromatography

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A method for the simultaneous determination of lipoic acid and/or Trolox methyl ether, along with α-, γ- and δ-tocopherol was developed using liquid chromatography-tandem mass spectrometry with negative electrospray ionization (HPLC-ESI-MS/MS) in an ion-trap mass spectrometer. Detection and quantification were accomplished by a multiple reaction monitoring method, using specific transitions from precursor ion to product ion for each analyte. Chromatographic separation was achieved in a 12 min run using a C(18) -bonded phase and methanol-aqueous ammonium acetate elution gradient. Linear correlations of the chromatographic peak area (r.u. × s(-1) ) to the injected amount (ng) gave the slope values (r.u. × s(-1) × ng(-1) ) 2.34 × 10(4) for α-tocopherol, 5.05 × 10(4) for γ-tocopherol, 1.27 × 10(5) for δ-tocopherol, 8.86 × 10(5) for lipoic acid and 1.23 × 10(5) for Trolox methyl ether. The lower limit of quantification ranged between 0.02 and 1.22 ng for Trolox methyl ether and lipoic acid. MS(3) experiments of γ- and δ-tocopherol suggest ion-radical reactions and dependence of the tocopherol fragmentation pattern on the phenolic ring methylation degree. The method is shown to be applicable to measurement of these metabolites in human serum after extraction.

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Section: Resultsmentioning

confidence: 99%

Determination of lipoic acid, Trolox methyl ether and tocopherols in human plasma by liquid‐chromatography and ion‐trap tandem mass spectrometry

Montero

Ramírez

Sánchez‐Guijo

et al. 2012

Biomedical Chromatography

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“…Mass spectrometry, when available, is the most advantageous tool in this field (Bustamante-Rangel et al, 2007;Schwartza et al, 2008).…”

Section: Introductionmentioning

confidence: 98%

Determination of Vitamin E in Coffee Beans by HPLC Using a Micro-extraction Method

Alves

Casal

2009

Food sci. technol. int.

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This work reports a solid-liquid micro-extraction method for vitamin E quantification in coffee beans (before and after roasting) with normal-phase HPLC/diode-array/fluorescence detection. The compounds were extracted after protein precipitation and overnight maceration (4 8C) in n-hexane, in the presence of butylated hydroxytoluene, using tocol as internal standard. The extraction method precision was inferior to 5% with mean recoveries near 100%. Chromatographic resolution from co-eluting interferences was achieved within 8 min with a 75 Â 3.0 mm (3 mm) silica column by using an isocratic elution with n-hexane/ 1,4-dioxane (98 : 2), at a flow rate of 0.7 mL/min. The diode-array detector was a valuable tool in the detection of co-eluting interferences and quantification was based on the fluorescence measurements. Only two vitamers, a-and b-tocopherol, were confirmed and quantified, being the latter generally the major compound in both arabica and robusta coffees. The present analytical method proved to be simple, sensitive, reproducible, accurate, allowing a fast quantification with low organic solvent consumption.

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“…The supercritical fluid extraction method has been used for the determination of tocotrienols and tocopherols in barley [21]. PLE has been used as sample treatment in wheat and rye samples to analyze these analytes before LC-MS determination [22].…”

Section: Introductionmentioning

confidence: 99%

Simultaneous extraction of tocotrienols and tocopherols from cereals using pressurized liquid extraction prior to LC determination

Delgado-Zamarreño¹,

Bustamante-Rangel

Sierra-Manzano

et al. 2009

J of Separation Science

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Original PaperSimultaneous extraction of tocotrienols and tocopherols from cereals using pressurized liquid extraction prior to LC determination Tocopherols and tocotrienols have been simultaneously determined in food samples using a rapid and simple analytical method including pressurized liquid extraction (PLE) and LC with electrochemical detection. Separation was carried out on a Phenomenex Synergi 4 lm Hydro-RP 80A column, using a solution of 2.5 mM acetic acid/sodium acetate in methanol/water (99:1, v/v) as mobile phase at a flow rate of 1.0 mL/min. Column temperature was maintained at 308C. Detection was performed by coulometric detection at 500 mV except for (b+c)-tocotrienol, in wheat and rye samples, which was at +350 mV. A palm oil containing a relatively large amount of c-tocotrienol and lower concentrations of a-and d-tocotrienols and a-and c-tocopherols was used to provide reference retention times for the tocotrienols. Analyte quantification was performed using the external standard method. The calibration equations of tocopherols were used to quantify both tocopherols and their corresponding tocotrienols. The extraction recoveries obtained using the optimized PLE conditions were in the 80 -114% range, with RSDs lower than 15%. The method was successfully applied to the determination of tocotrienols and tocopherols in cereal (wheat, rye, barley, maize and oat) and palm oil samples. IntroductionTocopherols (a-, b-, c-and d-T) and tocotrienols (a-, b-, cand d-T3) are lipophilic antioxidants, all of them designed vitamin E. They consist of a polar chromanol group and an apolar isoprenoid side chain. The isoprenoid tail of tocotrienols contains three unsaturated bonds, while the tail of tocopherols is fully saturated. The highest amounts of vitamin E are found in cereals and vegetable oils. Most vegetable oils and biological fluids contain varying amounts of tocopherols. Nevertheless, tocotrienols can be found in palm oil, coconut oil, and cereal grains such as wheat, rye, oats and barley. Functionally, vitamin E is a potent biological antioxidant that protects cytoplasmic membranes from oxidation and guards low-density lipoproteins from dangerous lipid peroxidation processes. Its antioxidant capacity and its ability to act as a free radical scavenger can reduce the risk of cancer and delay the progression of precancerous lesions. Tocotrienols reduce plasma cholesterol levels, as well as other lipids and non-lipids related to risk factors for cardiovascular diseases. In the field of cancer chemotherapy, tocotrienols display better antitumor activity than a-T [1]. Some authors state that tocotrienols have powerful neuroprotective, antioxidant, anti-cancer and cholesterol-lowering properties that often differ from the properties of tocopherols [2]. Since these eight vitamers have different antioxidant and biological activities, it is necessary to have separate quantitative data about each of them.The separation and quantification of tocotrienols and tocopherols are carried out mainly by chromatography, ...

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Determination of tocopherols and tocotrienols in cereals by pressurized liquid extraction–liquid chromatography–mass spectrometry

Cited by 73 publications

References 28 publications

Determination of lipoic acid, Trolox methyl ether and tocopherols in human plasma by liquid‐chromatography and ion‐trap tandem mass spectrometry

Determination of lipoic acid, Trolox methyl ether and tocopherols in human plasma by liquid‐chromatography and ion‐trap tandem mass spectrometry

Determination of Vitamin E in Coffee Beans by HPLC Using a Micro-extraction Method

Simultaneous extraction of tocotrienols and tocopherols from cereals using pressurized liquid extraction prior to LC determination

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