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1.
Teruo Miyazawa Hikoichiro Kunika Kenshiro Fujimoto Yasushi Endo Takashi Kaneda 《Lipids》1995,30(11):1001-1006
A reliable method was needed to analyze molecular species of oxidized vegetable oils. In order to accomplish this goal, mono-,
bis-, and tris-hydroperoxides (Mono-OOH, Bis-OOH, and Tris-OOH, respectively) of triacylglycerols formed during autoxidation
and photosensitized oxidation of oils were determined by reversed-phase high-performance liquid chromatography in combination
with chemiluminescence detection (CL-HPLC). Mono-OOH was the major species (96% of total hydroperoxides) in trioleoylglycerol
[peroxide value (PV) 0.16 meq/kg], and Bis-OOH and Tris-OOH showed prolonged accumulation with photooxidation. This profile
was confirmed in photooxidation of trilinoleoylglycerol and trilinolenoylglycerol. Soybean oil (PV 6 meq/kg) contained Mono-OOH
oleoyl-linoleoyl-linoleoylglycerol as the main peroxidic molecular species (50% of total hydroperoxides). Mono-OOH trilinoleoylglycerol
was the principal species (61% of total hydroperoxides) in safflower oil (PV 5 meq/kg), and Mono-OOH oleoyl-oleoyl-linoleoylglycerol
was the representative species (66% of total hydroperoxides) in olive oil (PV 3 meq/kg). The CL-HPLC method, which is specific
for the detection of hydroperoxides, should prove useful in studies of triacylglycerol oxidation in foods and vegetable oils. 相似文献
2.
Previous work in our laboratory demonstrated that soybean oil oxidation, expressed as PV, can be determined using NIR transmission
spectroscopy as an alternative to the official AOCS iodometric titration method. In the present study, a comparison of four
peroxide analytical methods was conducted using oxidized soybean oil. The methods included the official AOCS iodometric titration,
the newly developed NIR method, the PeroxySafe™ kit, and a ferrous xylenol orange (FOX) method, the latter two being colorimetric methods based on oxidation of iron. Five
different commercially available soybean oils were exposed to fluorescent light to obtain PV levels of 0–20 meq/kg; periodic
sampling was done to ensure having representative samples throughout the designated range. A total of 46 oil samples were
analyzed. Statistical analysis of the data showed that the correlation coefficient (r) and standard deviation of differences (SDD) between the standard titration and NIR methods were r=0.991, SDD=0.72 meq/kg; between titration and the PeroxySafe™ kit were r=0.993, SDD=0.56 meq/kg; and between the standard titration and FOX method were r=0.975, SDD=2.3 meq/kg. The high correlations between the titration, NIR, and PeroxySafe™ kit data indicated that these methods were equivalent. 相似文献
3.
Mette B. Let Charlotte Jacobsen Edwin N. Frankel Anne S. Meyer 《European Journal of Lipid Science and Technology》2003,105(9):518-528
The oxidative deterioration of milk emulsions supplemented with 1.5 wt‐% fish oil was investigated by sensory evaluation and by determining the peroxide value and volatile oxidation products after cold storage. Two types of milk emulsions were produced, one with a highly unsaturated tuna oil (38 wt‐% of n‐3 fatty acids) and one with cod liver oil (26 wt‐% of n‐3 fatty acids). The effect of added calcium disodium ethylenediaminetetraacetate (EDTA) on oxidation was also investigated. Emulsions based on cod liver oil with a slightly elevated peroxide value (1.5 meq/kg) oxidised significantly faster than the tuna oil emulsions, having a lower initial peroxide value (0.1 meq/kg). In the tuna oil emulsions the fishy off‐flavour could not be detected throughout the storage period. Addition of 5—50 ppm EDTA significantly reduced the development of volatile oxidation products in the cod liver oil emulsions, indicating that metal chelation with EDTA could inhibit the decomposition of lipid hydroperoxides in these emulsions. This study showed that an oxidatively stable milk emulsion containing highly polyunsaturated tuna fish oil could be prepared without significant fishy off‐flavour development upon storage, provided that the initial peroxide value was sufficiently low. 相似文献
4.
Gülgün Yildiz Randy L. Wehling Susan L. Cuppett 《Journal of the American Oil Chemists' Society》2002,79(11):1085-1089
NIR spectroscopy was used successfully in our laboratory to monitor oxidation levels in vegetable oils. Calibration models
were developed to measure PV in both soy and corn oils, using partial least squares (PLS) regression and forward stepwise
multiple linear regression, from NIR transmission spectra. PV can be measured successfully in both corn and soy oils using
a single calibration. The most successful calibration was based on PLS regression of first derivative spectra. When this calibration
was applied to validation sample sets containing equal numbers of corn and soy oil samples, with PV ranging from 0 to 20 meq/kg,
a correlation coefficient of 0.99 between titration and NIR values was obtained, with a standard error of prediction equal
to 0.72 meq/kg. For both types of oil, changes occurred in the 2068 nm region of the NIR spectra as oxidation levels increased.
These changes appear to be associated with the formation of hydroperoxides during oxidation of the oils. 相似文献
5.
Hyun Jung Kim Tae Shik Hahm David B. Min 《Journal of the American Oil Chemists' Society》2007,84(4):349-355
Fifteen milliliters of soybean oil having peroxide value (PV) of 0, 2, 4, 6, 8, or 10 meq/kg oil in a 35 mL serum bottle was
sealed air-tight with a Teflon rubber septum and aluminum cap and was stored in a forced-air oven at 50 °C. The oxidative
stability of soybean oil was evaluated daily for six days by measuring the headspace oxygen content and volatile compounds
in the headspace of a sample bottle by gas chromatography. As the initial PV of the oil increased from 0 to 2, 4, 6, 8 and
10, the headspace oxygen decreased and the volatile compounds increased at p < 0.05. Hydroperoxide accelerated the oxidation of soybean oil. The correlation coefficient (R
2) between the headspace oxygen and the volatile compounds was 0.95. The increase of tertiary butyl hydroquinone (TBHQ) from
0 to 50 ppm for the oil of PV 4 or 8 had a significant effect on the oxidative stability at p < 0.05. The increase from 50 to 100 ppm for the oil of PV 4 or 8 did not significantly increase the stability at p > 0.05. The oxidative stability of PV 8 meq/kg and 50 ppm TBHQ was better than the control with PV 0 and 0 ppm TBHQ at p < 0.05. TBHQ was an effective antioxidant to improve the oxidative stability of soybean oil. 相似文献
6.
Teruo Miyazawa Kenshiro Fujimoto Mikio Kinoshita Riichiro Usuki 《Journal of the American Oil Chemists' Society》1994,71(3):343-345
Thermoluminescence measurements can serve as a simple and rapid procedure for the estimation of peroxide content of soybean
oil. The thermoluminescence intensity, measured at 100°C, increases in proportion (r=0.978) to the peroxide value (from 0.5
to 18.0 meq/kg) of soybean oil, without any interference by the tocopherol contents. The emission spectrum had a maximum wavelength
at around 440–480 nm, suggesting that excited triplet carbonyls formed during thermal decomposition of hydroperoxides are
involved. The thermoluminescence measurement is readily available for the simple and rapid estimation of the peroxide content
of soybean oil, with no need for chemical reagents and delicate skills. 相似文献
7.
Abderrahmane Aït Kaddour Evane Grand Nathalie Barouh Bruno Bara Pierre Villeneuve Bernard Cuq 《European Journal of Lipid Science and Technology》2006,108(12):1037-1046
The present study was aimed at determining the ability of near‐infrared (NIR) spectroscopy to in situ describe fat oxidation kinetics in three different cereal‐based products: salted crackers (20% saturated palm oil and lauric oil, sprayed on surface); healthy crackers (10% unsaturated rapeseed oil, homogeneously distributed inside the product matrix); and moist pasteurised Asian noodles (1.5% unsaturated rapeseed oil, sprayed on surface). Products were stored under accelerated oxidation conditions at 40 °C. Lipid oxidation rates were determined from peroxide value (PV) measurements. We observed no significant changes in PV for the dry crackers (3 meq/kg after 60 days), a slight linear increase in PV for the healthy crackers (40 meq/kg after 60 days), and a rapid increase for the Asian noodles (80 meq/kg after 20 days). The NIR spectra were recorded between 1000 and 2500 nm by using a Fourier Transform NIR spectrometer, using an external probe. Measurements were done directly in situ on the product, on the ground samples, and on the extracted fat phase. The analysis of NIR spectral data by PLS statistical methods demonstrated some correlation trends (R2 = 0.575–0.897; RMSEC = 17–55%) for the products having a significant increase in PV. It was not possible to propose predictive models to calculate the oxidation rate. 相似文献
8.
In this study, the effect of deep fat frying on oil degradation, total phenols (TP) and total antioxidant activity (TAA) of
hazelnut, corn, soybean and olive oils were investigated. Oil degradation and oxidation were monitored by measuring the total
polar compounds (TPC) and the peroxide value (PV). The amount of TPC in corn, soybean and olive oils increased significantly
with the time increment (p < 0.05). The PV of the oils did not exceed the maximum acceptable limit of 10 mequiv O2/kg after 125 min frying except for hazelnut oil (10.64 mequiv O2/kg). Deep-fat frying did not cause any significant change in the TP of corn oil, soybean oil and olive oil (p < 0.05). A significant decrease in the antioxidant activity was observed after 50 min frying using hazelnut oil and corn
oil (p < 0.05). However, the antioxidant activity of soybean oil and olive oil significantly decreased after 75 and 25 min frying,
respectively. 相似文献
9.
Christina Bauer-Plank Lisette Steenhorst-Slikkerveer 《Journal of the American Oil Chemists' Society》2000,77(5):477-482
Triacylglyceride hydroperoxides (HPO-TAG), the primary autoxidation products of triacylglycerides (TAG), have been analyzed
in polyunsaturated vegetable oils by means of nonaqueous reversed-phase high-performance liquid chromatography (HPLC) with
ultraviolet detection. Using a retention time model based on equivalent carbon numbers, mono- and bishydroperoxy TAG and hydroxy
TAG could be identified. The correlation between the peroxide value (POV) determined by iodometric titration and quantitative
HPLC results for HPO-TAG was established for sunflower oil samples with POV between 0.5 and 50 meq/kg. The recovery of HPO-TAG
in the HPLC procedure was found to be close to 100% in the POV range of 4 to 71 meq/kg. Absolute quantitative results for
HPO-TAG in sunflower oil samples could not be obtained accurately, as molar extinction coefficients of HPO-TAG occurring in
natural oils deviate from those of available HPO-TAG reference compounds. 相似文献
10.
Partially hydrogenated oils (PHO) have been removed from the food supply due to adverse effects on risk for coronary heart disease (CHD). High-oleic soybean oils (HOSBO) are alternatives that provide functionality for different food applications. The objective of this study was to determine how consumption of diets containing HOSBO compared to other alternative oils, with similar functional properties, modifies LDL cholesterol (LDLc) and other risk factors and biomarkers of CHD. A triple-blind, crossover, randomized controlled trial was conducted in humans (n = 60) with four highly-controlled diets containing (1) HOSBO, (2) 80:20 blend of HOSBO and fully hydrogenated soybean oil (HOSBO+FHSBO), (3) soybean oil (SBO), and (4) 50:50 blend of palm oil and palm kernel oil (PO + PKO). Before and after 29 days of feeding, lipids/lipoproteins, blood pressure, body composition, and markers of inflammation, oxidation, and hemostasis were measured. LDLc, apolipoprotein B (apoB), NonHDL-cholesterol (HDLc), ratios of total cholesterol (TC)-to-HDLc and LDLc-to-HDL cholesterol, and LDL particle number and small LDL particles concentration were lower after HOSBO and HOSBO+FHSBO compared to PO (specific comparisons p < 0.05). Other than TC:HDL, there were no differences in lipid/lipoprotein markers when comparing HOSBO+FHSBO with HOSBO. LDLc and apoB were higher after HOSBO compared to SBO (p < 0.05). PO + PKO increased HDLc (p < 0.001) and apolipoprotein AI (p < 0.03) compared to HOSBO and HOSBO+FHSBO. With the exception of lipid hydroperoxides, dietary treatments did not affect other CHD markers. HOSBO, and blends thereof, is a PHO replacement that results in more favorable lipid/lipoprotein profiles compared to PO + PKO (an alternative fat with similar functional properties). 相似文献
11.
C. M. Fantoni A. P. Cuccio D. Barrera-Arellano 《Journal of the American Oil Chemists' Society》1996,73(2):251-253
Encapsulated fish oils are extensively commercialized in Brazil. These products could have an effect in the reduction of heart
diseases because of their high content of polyunsaturated fatty acids. However, information about their composition and quality
are still lacking. Fatty acid composition, oxidative stability (Rancimat, 80°C, 2.5 g sample and 8.3 L/h air), peroxide value
(PV), and polar compound content were determined in sixteen trademarked encapsulated fish and cod-liver oils, purchased from
Brazilian markets. The highly polyunsaturated fatty acid (eicosapentaenoic acid+docosahexaenoic acid) level appear to be typical
of marine oils (16.2 and 32.1%). The PV ranged from 2.1 to 20.3 meq/kg, which is considered high, whereas the Rancimat induction
periods varied from 1.95 to 8.45 h. The samples analyzed contained from 0.1 to 8.3% polar components. In some cases, both
composition and quality were inadequate for this kind of product. One of the samples did not contain cod-liver oil, it appears
that it contained soybean oil.
Presented at the 6th Latin American Congress and Exhibit on Fats and Oil Processing, LA-AOCS, Campinas, SP, Brazil, Sept.
1995. 相似文献
12.
Diets rich in polyunsaturated fatty acids (PUFA) are well known to suppress hepatic lipogenic enzymes compared to fat-free
diets or diets rich in saturated fatty acids. However, the mechanism underlying suppression of lipogenic enzymes is not quite
clear. The present study was undertaken to investigate whether lipid peroxidation products are involved in suppression of
lipogenic enzymes. Therefore, an experiment with growing male rats assigned to six groups over a period of 40 d was carried
out. Rats received semisynthetic diets containing 9.5% coconut oil and 0.5% fresh soybean oil (coconut oil diet, peroxide
value 5.1 meq O2/kg oil), 10% fresh soybean oil (fresh soybean oil diet, peroxide value 0.5 meq O2/kg oil), or 10% thermally treated soybean oil (oxidized soybean oil diet, peroxide value 74 meq O2/kg oil). To modify the antioxidant state of the rats, we varied the vitamin E supply (11 and 511 mg α-tocopherol equivalents
per kg of diet) according to a bi-factorial design. Food intake and body weight gain were not influenced by dietary fat and
vitamin E supply. Activities of hepatic lipogenic enzymes were markedly influenced by the dietary fat. Feeding either fresh
or oxidized soybean oil diets markedly reduced activities of fatty acid synthase, (FAS), acetyl CoA-carboxylase, (AcCX), glucose-6-phosphate
dehydrogenase, (G6PDH), 6-phosphogluconate dehydrogenase, and ATP citrate lyase (ACL) relative to feeding the coconut oil
diet. Moreover, feeding oxidized soybean oil slightly, but significantly, lowered activities of FAS, AcCX, and ACL compared
to feeding fresh soybean oil. Activities of hepatic lipogenic enzymes were reflected by concentrations of triglycerides in
liver and plasma. Rats fed the coconut oil diet had markedly higher triglyceride concentrations in liver and plasma than rats
consuming fresh or oxidized soybean oil diets, and rats fed oxidized soybean oil had lower concentrations than rats fed fresh
soybean oil. The vitamin E supply of the rats markedly influenced concentrations of thiobarbituric acid-reactive substances
in liver, but it did not influence activities of hepatic lipogenic enzymes. Because the vitamin E supply had no effect, and
ingestion of an oxidized oil had only a minor effect, on activities of hepatic lipogenic enzymes, it is strongly suggested
that neither exogenous nor endogenous lipid peroxidation products play a significant role in the suppression of hepatic lipogenic
enzymes by diets rich in PUFA. Therefore, we assumed that dietary PUFA themselves are involved in regulatio of hepatic lipogenic
enzymes. Nevertheless, the study shows that ingestion of oxidized oils, regardless of the vitamin E supply, also affects hepatic
lipogenesis, and hence influences triglyceride levels in liver and plasma. 相似文献
13.
Encapsulation of CO2-extracted sea buckthorn kernel oil and the stability of the products were investigated. Maltodextrin and an emulsifying starch
derivative were used for encapsulation by spray drying. Both shell materials significantly increased the storage stability
of sea buckthorn kernel oil, even though in maltodextrin capsules 10% of the total oil was extractable from the surface of
the capsule. The cornstarch sodiium octenyl succinate derivative capsules contained essentially no surface oil. After 9 wk
storage at controlled conditions (20°C, RH 50%), PV of the unencapsulated oil was above 90 meq/kg, whereas in the encapsulated
oils, the PV was still around 20 meq/kg. The PV of the encapsulated oil was dependent on the storage conditions. A small increase
in temperature (from 20 to 25–30°C) and a significant increase in humidity (from RH 50 to RH 50–70%) decreased the stability
of capsules. This was associated with the physical state of the microcapsule matrix and may be linked with glass transition
of the wall polymers. 相似文献
14.
P. M. Shiela Y. N. Sreerama A. G. Gopala Krishna 《Journal of the American Oil Chemists' Society》2004,81(12):1125-1129
The physicochemical characteristics and minor component contents of blended oils packed in pouches in relation to starting
oils used for blending were studied over a period of 6 mon at two storage temperatures and humidity conditions: 27°C/65% RH
and 40°C/30–40% RH. Color, PV, FFA value, β-carotene content, tocopherol content, and oryzanol content of the oils were monitored
at regular intervals. The color, PV (0.6–20.7 meq O2/kg, FFA value (0.08–2.1%), tocopherol content (360–1700 ppm%), oryzanol content (460–2,000 mg%), and sesame oil antioxidants
(400–2,000 mg%) were not changed in either the starting oils or their blends. Oils and oil blends containing a higher initial
PV (18.9–20.7 meq O2/kg) showed a slight reduction in value at 40°C, whereas oils having lesser PV of 5–10 showed a slight increase during the
storage period. Among the minor components studied, only β-carotene showed a reduction, 8.9–60.2% at 27°C and 48–71% at 40°C,
for the different oil blends studied. The observed results indicated that the packed oil blends studied were stable under
the conditions of the study, and the minor components, other than β-carotene, remained unaltered in the package even at the
end of 6 mon of storage. 相似文献
15.
Saga LC Rukke EO Liland KH Kirkhus B Egelandsdal B Karlsen J Volden J 《Journal of the American Oil Chemists' Society》2011,88(12):1883-1895
The oxidative stability of mixtures of edible oils containing polyunsaturated fatty acids (PUFA) and microcrystalline cellulose
(MCC) was investigated. The mixtures studied consisted of oils of either camelina (CAM), cod liver (CLO), or salmon (SO) mixed
with either colloidal or powdered MCC. A 50:50 (w/w) ratio of oil:MCC resulted in an applicable mixture containing high levels
of PUFA edible oil and dietary fiber. The oxidative stability of the formulated mixtures and the pure oils was investigated
over a period of 28 days. The peroxide value (PV) was assessed as a parameter for primary oxidation products and dynamic headspace
gas chromatography mass spectrometry (GC/MS) was used to analyze secondary volatile organic compounds (VOC). CAM and the respective
mixtures were oxidatively stable at both 4 and 22 °C during the storage period. The marine oils and the respective mixtures
were stable at 4 °C. At 22 °C, an increase in hydroperoxides was found, but no increase in VOC was detected during the time-frame
investigated. At 42 °C, prominent increases in PV and VOC were found for all oils and mixtures. Hexanal, a common marker for
the degradation of n-6 fatty acids, propanal and 2,4-heptadienal (E,E), common indicators for the degradation of n-3 fatty acids, were among the volatiles detected in the headspace of oils and mixtures. This study showed that a mixture
containing a 50:50 ratio of oil:MCC can be obtained by a low-tech procedure that does not induce oxidation when stored at
low temperatures during a period of 1 month. 相似文献
16.
Christina Skiera Panagiotis Steliopoulos Thomas Kuballa Ulrike Holzgrabe Bernd Diehl 《Journal of the American Oil Chemists' Society》2012,89(8):1383-1391
Within the course of lipid peroxidation, hydroperoxides are formed as primary products. They can be used as analytical markers
to assess the deterioration status of oils and fats. Here a new 1H-NMR assay to determine the hydroperoxide amount in edible oils is presented. We were able to show that the analytical performance
of the method is similar to that of the commonly used peroxide value (PV) according to Wheeler. A total of 290 edible oil
samples were analyzed using both methods. For some oil varieties considerable discrepancies were found between the results
obtained. In the case of black seed and olive oil, two substances could be identified that cause positive (black seed oil)
and negative (olive oils) deviations from the theoretical PV expected from the NMR values. 相似文献
17.
Evaluating Electron Paramagnetic Resonance (EPR) to Measure Lipid Oxidation Lag Phase for Shelf-Life Determination of Oils
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Leqi Cui Paul M. Lahti Eric A. Decker 《Journal of the American Oil Chemists' Society》2017,94(1):89-97
Lipid oxidation is one of the major causes of oil deterioration causing off-flavors and consumer rejection. Fast, easy, and dependable assays for predicting lipid oxidation rates in foods are important for shelf-life prediction. In this study, an electron paramagnetic resonance (EPR) spin-trapping technique with N-tert-butyl-α-phenylnitrone (PBN) was tested to determine the lag phase of lipid oxidation in stripped soybean oil (SSO), SSO with added α-tocopherol, and commercial soybean, canola and corn oils. EPR intensity of spin-trapped products from SSO correlated well with lipid hydroperoxides formation for samples stored at 37 and 55 °C respectively. When the antioxidant α-tocopherol was added, the EPR signal intensity of oil samples increased—indicating sample deterioration—after 50–65% of α-tocopherol was consumed. When using the EPR method with commercial soybean, canola or corn oil stored at 55 °C, there was a poor relationship between EPR intensity and lipid hydroperoxides lag phases. However, a linear correlation was found between EPR signal intensity and hexanal formation. For example, EPR signal intensity lag phases were 5, 13 and 27 days for soybean, canola and corn oils, respectively which was similar to the hexanal lag phases of 5, 13 and 25 days for the same oils. The EPR spin-trapping assay method has several advantages over headspace hexanal measurements, especially with regard to easier sample handling and shorter analysis times. 相似文献
18.
Nan Li Toshiaki Ohshima Kei-ichi Shozen Hideki Ushio Chiaki Koizumi 《Journal of the American Oil Chemists' Society》1994,71(6):623-627
In order to evaluate the effects of the degree of unsaturation of triacylglycerols on cholesterol oxidation, mixtures of purified
sardine oil triacylglycerols (iodine value, IV=182.6) and cholesterol; of partially hydrogenated sardine oil triacylglycerols
(IV=174.5) and cholesterol; and of fully hydrogenated sardine oil triacylglycerols (IV=92.0) and cholesterol were incubated
at 25°C in the dark. The oxidative stability of the samples decreased with increasing degree of unsaturation of the triacylglycerols
in the sample mixtures; the induction period for peroxide values (PV) of the sardine oil triacylglycerols and cholesterol
was shorter than that of the partially hydrogenated sardine oil triacylglycerols and cholesterol. Certain polyunsaturated
fatty acids (PUFAs) in the constituent fatty acids of sardine oil triacylglycerols started to decrease after a shorter induction
period compared with that of the partially hydrogenated triacylglycerols. The prominent cholesterol oxides accumulated in
the samples were 7β-hydroxycholesterol, 7-ketocholesterol, β-epoxide and cholestane triol. The tendency for accumulation of
cholesterol oxides in the time course coincided with the changes in PV as well as the decrease in PUFAs. Cholesterol was oxidized
in conjunction with autoxidation of coexisting fish oil triacylglycerols. Although lowering the degree of unsaturation of
fish oil triacylglycerols was effective in prolonging the induction period of cholesterol oxidation, the rate of cholesterol
oxidation in the cholesterol oxides' formation phase after the induction period was not affected by the difference in the
proportion of highly unsaturated fatty acids in the natural and partially hydrogenated triacylglycerols of fish oils. 相似文献
19.
Kangming Ma F. R. van de Voort A. A. Ismail Hualong Zhuo Binjing Cheng 《Journal of the American Oil Chemists' Society》2000,77(6):681-685
A Fourier transform infrared (FTIR) spectrometer equipped with an attenuated total reflectance (ATR) sample handling accessory
was used to rapidly monitor the peroxide value (PV) of oils undergoing catalytic oxidation to produce sulfonated fatliquors
used in the leather industry. PV quantitation was based on the stoichiometric reaction of triphenylphosphosphine (TPP) with
hydroperoxides to produce triphenylphosphine oxide (TPPO). By using a germanium ATR accessory that has a very short effective
pathlength, the spectral contributions of the base oil could be subtracted out, eliminating any oil-dependent intereferences
as well as providing a facile means of observing the spectral changes associated with the TPP/TPPO reaction. A calibration
was devised by adding a constant amount of TPP-saturated chloroform to oils containing varying amounts of tert-butyl hydroperoxide (TBHP) to produce TPPO that had a measurable band at 1118 cm−1. this band was linearly related to TBHP concentration and the calibration devised had an SD of ∼3.4 PV over the range of
0–250 PV. The ATR-PV method was standardized and the spectrometer programmed using Visual Basic to automate the analysis.
the automated FTIR-ATR method was found to be a convenient means of tracking PV of oils undergoing oxidation, and the results
correlated well with the PV values obtained using the AOAC iodometric method (r=0.94). The FTIR-ATR PV methodology provides a simple means of monitoring the PV of oils undergoing rapid oxidation and could serve
as a quality-control tool in the production of sulfonated oils for the leather industry. 相似文献