Esters butylated hydroxytoluene

Although alkyl- and aryllithium reagents usually attack the carbonyl group of a, j3-unsaturated carbonyl compounds (1, 2-addition), conjugate addition (1, 4-addition) is observed with very hindered esters where approach to the carbonyl group is impeded, as in 2,6-di-terr-butyl-4-methylphenyl esters (butylated hydroxytoluene, BHT esters) and 2,6-di-tert-butyl-4-methoxyphenyl esters (butylated hydroxyanisole BHA esters). ... 

It should be mentioned that the Food Additives Analytical Manual (FAAM) [75] provides analysts with FDA evaluated methodology (partly subjected to collaborative study) needed to determine compliance with food additive regulations, including procedures for indirect food additives, such as butylated hydroxy-anisole (BHA), butylated hydroxytoluene (BHT), t-butylhydroxyquinone (TBHQ), dilaurylthiopropionate (DLTDP), fatty acid methyl esters (FAME), sodium benzoate, sorbitol, and others. 

KJ Hammond. The determination of butylated hydroxyanisole (B.H.A.), butylated hydroxytoluene (B.H.T.) and individual gallate esters in fats and oils by high performance liquid chromatography. J Assoc Pub Anal 16 17-24, 1978. 

Ratio = blend ratio soybean oil fatty acid methyl esters (SME) in low-sulfur (<500ppm) No. 2 petrodiesel (LSD) where BO is 0% SME and B20 contains 20 vol% SME BHA = butylated hydroxyanisole BHT = butylated hydroxytoluene TBHQ = tert-butylhydroquinone. 

If stored at warm temperatures, glyceryl monostearate increases in acid value upon aging owing to the saponification of the ester with trace amounts of water. Effective antioxidants may be added, such as butylated hydroxytoluene and propyl gallate. 

Antioxidants are frequently added to unsaturated fats and oils in order to protect these against oxidative deterioration. For this reason, they are also added to a variety of food products containing unsaturated lipids. Antioxidants frequently applied are esters of gallic acid, butylated hydroxyanisole (BHA), butylated hydroxytoluene... 

Odor compounds may also be released from the plastic materials used in cars. The variety of plastics and possible chemical compounds is broad, which makes the identification of odor causing compounds an extremely comphcated task. An effective and rapid screening of VOCs and semi-VOCs from materials used in automobiles was developed by utihzing the SPME technique [28]. The low molecular weight compoimds extracted from five different automobile materials included different benzene derivatives, aldehydes, esters, biphenyls, phthalates, butylated hydroxytoluene, phenols, alcohols, styrene, triethylene-diamine, carboxylic acids and ketones. A considerable munber of VOCs and semi-VOCs were detected, indicating that more attention should be paid to the selection of materials and additives for automotive parts. 

Preservatives Antimicrobial Benzalkonium chloride Benzyl alcohol Chlorhexidine Imidazolidinyl urea Phenol Potassium sorbate 1 Benzoic acid Bronopol Chlorocresol Paraben esters Phenoxyethanol Sorbic acid Antioxidants a-Tocopherol Ascorbic acid Ascorbyl palmitate Butylated hydroxyanisole Butylated hydroxytoluene Sodium ascorbate Sodium metabisulphite Chelating agents Citric acid Edetic acid... 

Alternative Pathway Butylated Hydroxytoluene Butylated Hydroxyanisole Caffeoyl Ester Unit Contact Growth Index Classical Pathway Dichloroethane Influenza Virus A Glucose... 

Lipid Composition. After the behavior experiments, the rats were killed by decapitation. Tissue samples including brain and retina were removed and stored at -80°C. The total lipid extracts of tissues were prepared according to the method of Folch et al. (39). Butylated hydroxytoluene (300 qg/sample) was added in methanol to each sample to minimize lipid oxidation. The total lipid extracts were trans-methylated with 14% BFj/methanol at 100°C for 60 min by a modification (40) of the method of Morrison and Smith (41). Fatty acid methyl esters were then analyzed on a Hewlett-Packard 5890 gas chromatograph (Hewlett-Packard, Palo Alto, CA) equipped with a flame ionization detector and fused silica capillary column (DB-FFAP, 30 m X 0.25 mm x 0.25 m, J W, Folsom, CA) with carrier gas (hydrogen) at a linear velocity of 50 cm/s. Injector and detector temperature were set to 250°C and oven temperature program was as follows 130 to 175°C at4°C/min, 175 to 210°C at l°C/min, and then to 245 at 30°C/min, with a final... 

Some modifications were proposed by Chuang and Brunner in this supercritical fluid extraction process to contour the low selectivity that they have previously observed [63]. The authors utilized a process of transesterification of palm oil and subsequently after the three-step extraction obtains a product 200-fold concentrated in carotenoids but virtually absent of esters, fatty acids, and triglycerides. Nevertheless, the temperature used (60 °C) and the presence of O2 in supercritical CO2, conditions that lead to carotenoid degradation, require addition of antioxidants (such as butylated hydroxytoluene) to the process [64]. 

When measuring the level of nonpolar retinoids in blood, a modified method of Thompson et al, (1971) could be used (see also Varma and Beaton, 1972 Bieri et al., 1979 Ross, 1981). Briefly, the plasma or serum (100-200 xl) is mixed with 1 volume of internal standard solution (e.g., retinyl acetate) in ethanol. To the mixture is added 1-4 volumes of hexane the contents are mixed well and then centrifuged. The hexane (upper phase) is carefully removed and used for chromatography or other analyses. For added protection against oxidation, butylated hydroxytoluene (100 xg/ml) can be added to the hexane. Other solvents used for extraction of retinol and its esters from serum include chlo-roform methanol (see, for example, DeRuyter and De Leenheer, 1978) and hexane methylene chlorideiisopropanol (Besner /., 1980). Recoveries, when reported, range near 100%. 

Figure 3.2 Separation of fatty acid methyl esters by gas-liquid chromatography on a 2mx4mm column. Stationary phase 10% polyethylene glycol adipate (stabilized with orthophosphoric acid) on Diatomite C-AAW. Carrier gas argon. Flow rate 50ml/1 min. The oven temperature was programmed from 65°C to 185°C at 8°C per min. The sample consists of fatty acids derived from a milk diet for calves. Heptanoic and heptadecanoic acids were added as internal standards in concentrations of 1.55 mg 7 0 and 4.94 mg 17 0 in 10 ml sample solution and the computer was programmed to print out the concentration in mg/10 ml of each fatty acid In the mixture. IS = internal standard BHT = butylated hydroxytoluene (antioxidant). Reproduced with kind permission of Mr J.D. Edwards-Webb.

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