What exactly are fatty acids?
Fatty acids (FAs) are long-chain carbon compounds bearing a carboxyl group (–COOH)—the “building blocks” of the lipid world. They can exist as free fatty acids (FFAs), and they are also commonly “assembled” into more complex lipid structures such as triacylglycerols (TAGs), phospholipids, and cholesteryl esters.
There are three core variables that define a fatty acid:
1. Carbon chain length (e.g., C4, C16, C22…)
2. Degree of unsaturation (0, 1, or multiple C=C double bonds)
3. Double-bond position and geometry (ω/n-3, n-6; cis/trans)
Structure and nomenclature: explaining “ω-3/6/9, 18:2, Δ9” in one place
1. Three commonly used notations (most common in labs)
(1) C:D notation: e.g., 18:1 (18 carbons, 1 double bond)
(2) Δ (delta) notation: number carbons starting from the –COOH end (carboxyl carbon = 1).
Δ9 means the double bond is between C9–C10, e.g., 18:1Δ9.
(3) ω/n notation (n-3 / n-6): looks only from the CH₃ end (ω end).
n-x (= ω-x) indicates that the double bond closest to the CH₃ end lies between the x-th and (x+1)-th carbons counted from the CH₃ end. This is a family concept (widely used in nutrition and biology).
Examples:
ALA is written as 18:3 n-3, meaning the double bond nearest the CH₃ end belongs to the n-3 (ω-3) family.
LA is written as 18:2 n-6, meaning the double bond nearest the CH₃ end belongs to the n-6 (ω-6) family.
This notation is often used to describe differences between the ω-3 and ω-6 metabolic pathways and their downstream products.
ω/n family rules commonly used in nutrition/biology
1. n-3 (ω-3): counting from the CH₃ end, the nearest double bond is between ω-3 and ω-4 (i.e., between the 3rd and 4th carbons from the CH₃ end).
2. n-6 (ω-6): counting from the CH₃ end, the nearest double bond is between ω-6 and ω-7 (i.e., between the 6th and 7th carbons from the CH₃ end).
2. cis vs trans: why they change melting point, membrane fluidity, and experimental outcomes
1. Naturally occurring unsaturated fatty acids are mostly cis. A cis double bond introduces a “kink” in the chain, making tight packing harder and usually increasing fluidity.
2. Trans geometry is closer to a straight chain and can pack more tightly, behaving more like saturated fatty acids.
3. Therefore, in membrane models or cell experiments, cis/trans differences do not only affect melting point and fluidity—they can also alter the membrane-protein environment, lipid droplet phase behavior, and lipotoxicity thresholds, leading to observable phenotype differences.
Fatty acid classification quick-reference table
Classification dimension | Subclass (common abbreviation) | Representative examples | Typical research / experimental uses |
Chain length | SCFA short-chain (C2–C6) | Propionic acid, butyric acid, valeric acid, caproic acid | Metabolism/microbiome-related models, acidic controls, esterification precursors |
Chain length | MCFA medium-chain (C8–C12) | Caprylic acid, capric acid, lauric acid | Emulsification/dispersion systems, lipid carrier models, tuning hydrophobic chain effects in materials |
Chain length | LCFA long-chain (C14–C18) | Myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid | Cellular lipotoxicity models, membrane/lipid droplet studies, surface modification |
Chain length | LC-PUFA long-chain polyunsaturated (≥C20, ≥2 double bonds) | DGLA (20:3), AA (20:4), EPA (20:5), DPA (22:5), DHA (22:6) | Lipid mediators & inflammation–resolution pathways, membrane-lipid remodeling, lipidomics controls |
Chain length | VLCFA very-long-chain (≥C22) | Behenic acid (22:0), erucic acid (22:1) | Peroxisomal metabolism / myelin sphingolipid relevance, extra-long hydrophobic-chain material and phase-behavior controls |
Unsaturation | SFA saturated | Palmitic acid (16:0), stearic acid (18:0) | Lipotoxicity controls, crystallization/phase behavior, metal soaps/salts preparation |
Unsaturation | MUFA monounsaturated | Oleic acid (18:1), palmitoleic acid (16:1), trans C18:1 | Membrane fluidity controls, cis/trans comparisons |
Unsaturation | PUFA polyunsaturated | LA (18:2), ALA (18:3), AA (20:4), EPA (20:5), DHA (22:6) | Precursors for inflammatory mediators and signaling pathways, oxidation sensitivity studies |
Double-bond family | n-3 / n-6 | ALA/EPA/DHA; LA/AA, etc. | Family metabolism (elongation/desaturation) and competition; membrane phospholipid composition & remodeling; lipid mediator production (AA/EPA → eicosanoids; EPA/DHA → pro-resolving mediators) |
How fatty acids are used in research and experiments: three main tracks
Track A: Cell/molecular experiments—what are you doing when you “add fatty acids to cells”?
Common goals include inducing lipotoxicity, studying membrane lipid changes, probing signaling pathways, and modeling high-fat environments. However, FFAs have poor water solubility, readily adsorb to surfaces, oxidize easily, and can precipitate. A key determinant of reproducibility is therefore:
(1) Prefer delivery as a “fatty acid–BSA complex”
Use fatty acid–free BSA to “load” fatty acids into a controllable system. Different FA:BSA ratios can strongly affect the effective bioavailable fatty acid concentration.
Note (typical ranges and physiological reference):
In human plasma, FA:albumin is often around 1:1 to 3:1, and can rise to >5:1 in certain pathological/stress states. In cell models, 2:1 to 6:1 is commonly used (many protocols use 5:1 or close to 6:1) to tune “free fatty acid stress.”
Be aware: if the ratio is too high or preparation is suboptimal, the solution may become turbid or form microdroplets. In that case, the nominal concentration no longer represents the cell-available concentration.
(2) If using an organic-solvent stock (ethanol/methanol/DMSO, etc.)
Control the final solvent concentration, include a solvent control, and avoid cold precipitation.
Practical note: Details of preparation and delivery (temperature, pH, ratio, pre-warming) can strongly affect outcomes. FA:BSA ratios vary widely across the literature, so it’s best to state the method clearly and run a small pilot calibration.
Track B: Analytical measurement—the two most common routes for “measuring fatty acids”
1) Fatty acid composition analysis (GC-FID / GC-MS)
Typically, fatty acids are converted into a more volatile, GC-friendly form: FAMEs (fatty acid methyl esters). Common routes include acid-catalyzed methylation (BF₃–MeOH, HCl–MeOH, etc.) and base-catalyzed transesterification (NaOMe).
BF₃–MeOH is widely used, but under high temperature/long reaction time or in the presence of water, it may reduce recovery of highly unsaturated fatty acids and introduce by-products. If samples are rich in PUFAs, consider milder acid methanol systems (e.g., HCl–MeOH) or a two-step approach: NaOMe (transesterify first) + acid-catalyzed step (esterify free acids after). Use internal standards and mixed standards to verify recovery and peak shape.
2) Lipidomics / total lipid extraction (primarily LC-MS)
Classic extraction systems include Folch (chloroform/methanol 2:1), Bligh & Dyer (chloroform/methanol/water), and the MTBE method, which is often more suitable for high-throughput lipidomics.
Track C: Oxidation and stability—PUFA studies can’t avoid this
PUFAs (especially EPA/DHA/AA) oxidize very easily. In experiments, sometimes you need to prevent oxidation to avoid confounding results, and sometimes you need to measure how much oxidation occurred.
1. Preventing oxidation: antioxidants (e.g., α-tocopherol, BHT), light protection, low temperature, inert-gas headspace, minimizing freeze–thaw cycles and bottle-open time.
2. Measuring oxidation: the TBARS assay reacts TBA with MDA and related lipid peroxidation products to form a colored adduct. It is a common entry-level method, but it measures “TBARS equivalents.”
Important: TBARS is not absolutely specific to MDA or lipid peroxidation and is highly sensitive to acidity, heating time, and sample matrix. It is better suited for between-group trend comparisons. For more reliable absolute quantification, consider HPLC/LC-MS (or more specific derivatization-based assays) to measure MDA, 4-HNE, isoprostanes, and related markers.
Selection decision table: Which form should you choose—“free acid / fatty acid salt / FAME / TAG / CLA / auxiliaries & reagents”?
Experimental goal | Preferred “chemical form” | Why | Product examples | Common pitfalls & how to avoid them |
Cell treatment, signaling pathways, lipotoxicity models | Free fatty acid + delivery via fatty acid–free BSA | Controls effective concentration and bioavailability | Free acids (SFA/MUFA/PUFA); BSA solution | Adding free acids directly often precipitates/adsorbs; different FA:BSA ratios can cause large effect differences |
Quantitative “fatty acid composition” (GC) | FAME standards + methylation derivatization reagents | FAMEs are more volatile, better for GC quantification and retention-time matching | FAME (analytical standards); BF₃–MeOH | Incomplete derivatization or overreaction; water and acid catalysis can cause side reactions (strictly control conditions) |
Total lipid extraction / lipidomics (LC-MS) | Extraction solvent systems (Folch / B&D / MTBE) | High recovery; compatible with multiple lipid classes | Chloroform/methanol/MTBE/hexane, etc. | Phase separation and salt-water ratios affect recovery; different methods have different lipid-class biases |
Emulsification/interface/soap formation; formulation structurant | Fatty acid salts (Na⁺/K⁺ salts) or salt formed from free acids | Directly provides surfactancy and ionic headgroups | Sodium/potassium oleate, sodium palmitate, sodium stearate | Divalent ions readily form insoluble salts; pH shifts can cause precipitation or abrupt property changes |
Oil phase/lipid droplet models; crystallization phase behavior | TAG (triacylglycerol) | Model oil phase closer to natural lipid droplet form | Triolein / Tripalmitin, etc. | Purity and solid–liquid phase affect particles and crystallization; temperature control is critical |
Mechanistic controls for conjugated fatty acids | Prefer single-isomer CLA | Isomer ratios strongly affect biological effects and comparability | Single-isomer CLA / mixtures | Mixtures are suitable for screening; mechanistic studies should use single-isomer controls whenever possible |
Methodological checklist (key precautions)
1) Storage and oxidation control (especially for PUFAs)
1. Protect from light, store cold, minimize bottle opening, minimize freeze–thaw cycles (aliquoting is crucial).
2. Use antioxidants when needed (e.g., BHT, α-tocopherol) and record the added amount.
3. For highly unsaturated fatty acids, use inert-gas headspace when possible and amber bottles.
2) Delivery and controls in cell experiments
1. FA–BSA complexes are more controllable than adding free acids directly; clearly report FA:BSA ratio, temperature, and solvent residue.
2. Include controls: BSA control, solvent control, and equimolar fatty-acid controls (e.g., SFA vs MUFA vs PUFA).
3. Watch for precipitation: if you see “oil droplets/flocculates,” the effective concentration may already be out of control.
3) GC / derivatization
1. Methylation reagents and acidic conditions are moisture-sensitive; dry glassware and control solvent water content.
2. Run in parallel: blanks, internal standards, mixed standards, and replicates—avoid mistaking “derivatization variability” for “biological differences.”
4) TBARS (lipid oxidation)
1. TBARS measures “TBARS equivalents” and is better for trend comparisons; report conditions (acidity, temperature, time).
2. MDA standards often use stable precursors (e.g., acetal-type compounds) to release MDA—follow method instructions strictly.
Frequently Asked Questions (FAQ)
Q1: Are all animal fats (except fish oil) saturated fatty acids?
A: No. Animal fats generally have a higher proportion of saturated fatty acids, but they also contain substantial monounsaturated fatty acids (e.g., oleic acid). Whether a fat is solid or liquid at room temperature depends mainly on unsaturation, chain length, and cis/trans geometry, not a simple “animal vs plant” dichotomy.
Q2: If I dissolve fatty acids in ethanol and add them directly to cells, does that mean the cells receive the same fatty acid concentration?
A: Not necessarily. Free fatty acids can form microdroplets/precipitates in aqueous media, adsorb to plastic surfaces, and their effective concentration is strongly delivery-dependent. For cell experiments, it is generally recommended to prepare FA–BSA complexes using fatty acid–free BSA, with strict solvent/BSA controls.
Q3: For GC-based fatty acid analysis, can I inject without derivatization?
A: In most cases, no. Free fatty acids often have poorer volatility and peak shape than FAMEs, and quantitative libraries and retention-time references are commonly based on FAMEs. The standard workflow is to methylate to FAMEs first, then run GC-FID/GC-MS.
Q4: Is it okay to keep EPA/DHA/AA and other PUFAs at room temperature or to repeatedly freeze–thaw them?
A: Not recommended. PUFAs oxidize easily. Storage and handling should emphasize: light protection, low temperature, minimal opening, minimal freeze–thaw, optional antioxidants when needed, and minimizing air exposure time. Otherwise, oxidation by-products can become a major source of experimental variability.
Q5: Online sources often say “CLA (conjugated linoleic acid) is beneficial for health/fat loss.” Can I treat CLA as a single component for discussion or experiments?
A: No—do not treat it as “one single ingredient” by default. CLA is not a single molecule, but a collective term for different isomers of conjugated linoleic acid. Common major isomers include c9,t11-CLA and t10,c12-CLA, and different isomers can produce different—sometimes even opposite—biological effects.
So when you see claims like “CLA is beneficial,” it usually means that effects were observed under specific isomers, specific ratios, doses, subjects, or models, and such results cannot be automatically generalized to all CLA products or all experimental conditions.
Aladdin Representative Product Table for Fatty-Acid Research and Analysis
(Core molecules + supporting reagents + pretreatment solvents/standard solutions)
A “chemical map for experiments,” logically organized into:
1. Target molecules: free fatty acids (SFA/MUFA/PUFA, including trans fats/CLA), fatty-acid salts, TAGs, FAMEs
2. Delivery & systems: fatty acid–free BSA, and (if needed) the chelator EDTA (evaluate suitability for cell experiments)
3. Analysis & pretreatment: extraction solvents such as chloroform/methanol/MTBE/hexane; derivatization reagents such as BF₃–MeOH
4. Stability & detection: antioxidants (α-tocopherol, BHT); TBARS reagents (TBA) and an MDA precursor
① Core fatty acids (free acids) and key mechanistic controls
Category | CAS No. | Aladdin Cat. No. | Name | Specification / Purity | Key features or typical applications |
ω-6 LC-PUFA (free acid, analytical standard) | 506-32-1 | Arachidonic acid (AA) | Moligand™, analytical standard, ≥99% (GC) | Eicosanoid precursor; key control for inflammatory mediators/signaling pathway studies | |
ω-3 LC-PUFA (free acid, high-purity research grade) | 6217-54-5 | cis-4,7,10,13,16,19-Docosahexaenoic acid (DHA) | Moligand™, ≥98% | DHA; commonly used in neuroscience/membrane-lipid studies and oxidation-sensitivity research | |
ω-3 LC-PUFA (free acid, analytical standard) | 10417-94-4 | cis-5,8,11,14,17-Eicosapentaenoic acid (EPA) | Moligand™, analytical standard | EPA; ω-3 long-chain PUFA control and composition analysis standard | |
ω-6 PUFA (free acid, analytical standard) | 60-33-3 | Linoleic acid | Moligand™, analytical standard, ≥99% (GC) | Essential ω-6 fatty acid; membrane fluidity/metabolism studies and quantitative control | |
ω-3 PUFA (free acid, analytical standard) | 463-40-1 | Linolenic acid (α-Lnn) | Moligand™, analytical standard, ≥99% | ALA (ω-3) essential fatty acid; pathway studies and control experiments | |
ω-6 PUFA (free acid, high-purity research grade) | 506-26-3 | γ-Linolenic acid | Moligand™, ≥97% | GLA (ω-6); commonly used in metabolism/inflammation mechanism studies | |
Long-chain PUFA (free acid, analytical standard) | 24880-45-3 | Docosapentaenoic acid | Analytical standard | DPA (22:5) control; long-chain PUFA composition analysis/method validation | |
PUFA ready-to-use solution (in ethanol) | 1783-84-2 | cis-8,11,14-Eicosatrienoic acid | Moligand™, ≥99%, 100 mg/mL in ethanol | DGLA (20:3) mechanistic control; ready-to-use ethanol solution for accurate dosing | |
MUFA (oleic acid, pharmaceutical grade) | 112-80-1 | Oleic acid | Pharmaceutical grade, PharmPure™ | Common in emulsions/lipid systems; often used in cell studies as a “lipotoxicity-relief” control | |
MUFA (ω-7, analytical standard) | 373-49-9 | cis-9-Hexadecenoic acid | Moligand™, analytical standard | Palmitoleic acid (16:1); control for metabolic/signaling-lipid studies | |
Long-chain MUFA (free acid, high-purity GC) | 112-86-7 | Erucic acid | ≥99% (GC) | Erucic acid (22:1); control for oil composition/material hydrophobic-chain comparisons | |
trans MUFA (free acid, analytical standard) | 112-79-8 | Elaidic acid | Analytical standard, ≥99% (GC) | trans-C18:1 control; cis/trans impact studies | |
trans MUFA (free acid, high-purity research grade) | 693-72-1 | 11-trans-Octadecenoic acid | ≥99% | trans-C18:1 positional/geometric control; membrane-property comparisons | |
Long-chain SFA (C16:0) | 57-10-3 | Palmitic acid | Stearic acid ≤0.5% | Common FA for lipotoxicity and membrane/lipid-droplet models; synthesis feedstock | |
Long-chain SFA (C18:0) | 57-11-4 | Stearic acid | Moligand™, suitable for synthesis | Metal soaps/surface modification/materials and formulation structurant | |
Long-chain SFA (C14:0) | 544-63-8 | Myristic acid | Moligand™, suitable for synthesis | Myristoylation-related research; synthesis and material-chain incorporation | |
Very-long-chain SFA (C22:0) | 112-85-6 | Behenic acid (docosanoic acid) | Technical grade, ≥85% | Waxy long chain; hydrophobic modification/coatings/material systems and salt-formation precursor | |
MCFA (C8:0) | 124-07-2 | Caprylic acid | Moligand™, suitable for synthesis | MCFA; commonly used in emulsions/dispersion/lipid nanocarrier systems | |
MCFA (C10:0) | 334-48-5 | Decanoic acid (n-decanoic acid) | Moligand™, chemical pure (CP), ≥98% | MCFA; common in formulations/materials and metabolic models | |
MCFA (C12:0) | 143-07-7 | Lauric acid | Moligand™, suitable for synthesis | Surfactant/esterification feedstock; MCFA model | |
SCFA (C4:0) | 107-92-6 | Butyric acid | Moligand™, suitable for synthesis | SCFA model; synthesis/esterification precursor (also widely used as a biological tool) | |
SCFA (C5:0) | 109-52-4 | Valeric acid (n-valeric acid) | Moligand™, chemical pure (CP), ≥98% | SCFA model; synthesis/esterification precursor and control acid | |
SCFA (C6:0) | 142-62-1 | Hexanoic acid (n-hexanoic acid) | Chemical pure (CP), ≥98% | SCFA/odor-acid model; synthesis and esterification precursor | |
SCFA (C3:0) / culture supplement | 79-09-4 | Propionic acid | For insect cell culture, ≥99.5% | SCFA model; additive for insect cell culture/metabolism studies |
② Supporting reagents selection table for fatty-acid research & analysis
(CLA / fatty-acid salts / FAME / TAG / antioxidants & oxidation assays / cell delivery / derivatization)
Category | CAS No. | Aladdin Cat. No. | Name | Specification / Purity | Key features or typical applications |
Conjugated fatty acid (single CLA isomer) | 2540-56-9 | Conjugated (9Z,11E)-linoleic acid | ≥98% | Single-isomer control; avoids result differences caused by mixed isomers | |
Conjugated fatty acid (CLA isomer mixture) | 2420-56-6 | Conjugated linoleic acid | Isomer mixture, Moligand™, ≥80% | CLA mixture; suitable for overall-effect screening (pay attention to isomer ratio) | |
Fatty-acid salt / pharmaceutical excipient grade (sodium salt) | 822-16-2 | Sodium stearate | PharmPure™, USP | Pharmaceutical/excipient and formulation structurant; stricter quality system | |
Fatty-acid salt (sodium salt) | 408-35-5 | Sodium palmitate | ≥97% (GC) (T) | Surfactant/dispersion and formulation structurant; note pH and divalent-ion precipitation risk | |
Fatty-acid salt (sodium salt) | 143-19-1 | S598955 | Sodium oleate | Industrial grade | Emulsification/micelles/interfacial systems; common in dispersion and cleaning systems |
Fatty-acid salt (potassium salt) | 143-18-0 | Potassium oleate | Chemical pure (CP) | Surfactancy/emulsification; interfacial-behavior research and salt-forming systems | |
FAME (analytical standard) | 112-63-0 | Methyl linoleate | Analytical standard, ≥99% (GC) | Common standard for GC-FID/GC-MS composition quantification | |
FAME (analytical standard) | 301-00-8 | Methyl linolenate | Analytical standard | PUFA FAME standard; composition analysis/method validation | |
FAME (analytical standard) | 112-39-0 | Methyl palmitate | Analytical standard, ≥99% (GC) | SFA FAME standard; retention-time/response control | |
Fatty acid methyl ester (reagent grade / control) | 112-62-9 | Methyl oleate | Chemical pure (CP), ≥60% (GC) | Ester control/nonpolar component reference; method development and material screening | |
Fatty acid methyl ester (mixture) | 112-61-8 | Methyl stearate | Mixture | Ester model/intermediate; “mixture” attribute makes it more suitable for screening | |
Model lipid (TAG) | 122-32-7 | Glyceryl trioleate (Triolein) | Chemical pure (CP), ≥60% | Triolein; model oil phase for lipid droplets/emulsions/lipid-carrier systems | |
Model lipid (TAG) | 555-44-2 | Glyceryl tripalmitate (Tripalmitin) | ≥98% | Tripalmitin; solid lipid phase model for crystallization and structured-lipid studies | |
Antioxidant (natural) | 59-02-9 | (+)-α-Tocopherol | From V-type vegetable oil, ~1000 IU/g | Vitamin E; antioxidant stabilization for PUFA/oil systems | |
Antioxidant (synthetic) | 128-37-0 | 2,6-Di-tert-butyl-p-cresol (BHT) | Chemical pure (CP) | BHT; suppresses autoxidation, stabilizes samples/solvents and serves as a control | |
Lipid-oxidation assay reagent (TBARS) | 504-17-6 | 2-Thiobarbituric acid | Moligand™, ≥98% | Color reagent for TBARS assay; lipid peroxidation detection | |
Oxidation detection / standard precursor | 102-52-3 | 1,1,3,3-Tetramethoxypropane | ≥98% | MDA-related calibration precursor; TBARS method QC | |
Carrier protein (fatty-acid delivery) | 9048-46-8 | Albumin solution, from bovine serum | Sterile-filtered, for cell culture, low endotoxin, 10% in DPBS, fatty acid free | For preparing FA–BSA complexes; fatty acid–free + low endotoxin improves reproducibility | |
Chelator / culture additive | 6381-92-6 | Disodium EDTA dihydrate | For plant cell culture, ≥99% | Chelates Fe/Cu and other metal ions; inhibits metal-catalyzed oxidation; medium preparation | |
Derivatization reagent (FAME preparation) | 373-57-9 | Boron trifluoride–methanol | 50 wt.% solution in MeOH | BF₃–MeOH methylation reagent; fatty-acid GC pretreatment |
③ Supporting solvents / standard solutions / basic reagents
(Sample pretreatment and method-development support)
Category | CAS No. | Aladdin Cat. No. | Name | Specification / Purity | Key features or typical applications |
Chromatography/MS-grade solvents & mobile-phase additive | 67-56-1 | M433272 | Methanol solution | MS grade (MS), UltraPureChrom™, UHPLC grade, ≥99.5%, contains 0.10% (v/v) formic acid | For LC-MS/UHPLC mobile phases; formic acid aids ionization and peak-shape optimization |
General solvent (prep/chromatography grade) | 67-63-0 | Isopropanol (IPA) | Preparative chromatography grade, ≥99.8% | Common solvent for cleaning/pretreatment/preparative chromatography | |
Halogenated solvent (HPLC) | 67-66-3 | C1506336 | Chloroform (regulated precursor chemical) | For HPLC, ≥99.5%, contains amylenes as stabilizer | Common for lipid extraction/liquid–liquid partitioning and as a chromatographic solvent |
Halogenated solvent (anhydrous) | 75-09-2 | D433565 | Dichloromethane | Anhydrous, ≥99.8%, contains 40–150 ppm amylene as stabilizer | Anhydrous reactions/extraction solvent; often used in lipid-related organic-phase operations |
Ether solvent (anhydrous) | 1634-04-4 | Methyl tert-butyl ether (MTBE) | Anhydrous, ≥99.8% | Common solvent system for lipid extraction/pretreatment | |
Nonpolar solvent (alkane) | 110-54-3 | n-Hexane | For environmental analysis | Oil/fatty-acid extraction and sample cleanup; commonly used in environmental analysis | |
Nonpolar solvent (alkane, anhydrous) | 142-82-5 | n-Heptane | Anhydrous, ≥99% | Nonpolar system preparation; common for extraction/cleaning and GC pretreatment | |
General organic acid / acidification reagent | 64-19-7 | Glacial acetic acid | Superior grade reagent, ≥99.5% | pH adjustment/acetate systems; common for sample acidification and synthesis | |
Analytical standard solution / quantitative calibration | 540-84-1 | Isooctane standard solution in tetrachloroethylene | Mass concentration 1000 mg/L, U = 16 mg/L | Standard solution for method setup and instrument quantitative calibration |
Note: The above list contains Aladdin representative products only. For more specifications, please refer to the product list at the end of the full document or search the official website using the CAS number/product name.
Appendix: Abbreviations
1. SCFA: Short-Chain Fatty Acids (commonly C2–C6)
2. MCFA: Medium-Chain Fatty Acids (commonly C8–C12)
3. LCFA: Long-Chain Fatty Acids (commonly C14–C18)
4. VLCFA: Very-Long-Chain Fatty Acids (commonly ≥C20)
5. SFA: Saturated Fatty Acids (no C=C double bonds)
6. MUFA: Monounsaturated Fatty Acids (one C=C double bond)
7. PUFA: Polyunsaturated Fatty Acids (≥2 C=C double bonds)
8. n-3 / ω-3: omega-3 family fatty acids (first double bond near the 3-position from the methyl end)
9. n-6 / ω-6: omega-6 family fatty acids (first double bond near the 6-position from the methyl end)
10. ω-9 / n-9: omega-9 family fatty acids (first double bond near the 9-position from the methyl end)
11. FFA: Free Fatty Acids (fatty acids not esterified to glycerol/other backbones)
12. TAG: Triacylglycerols / Triglycerides (triesters formed from three fatty acids and glycerol)
13. FAME: Fatty Acid Methyl Esters (methylated derivatives of fatty acids; commonly used for GC analysis)
14. CLA: Conjugated Linoleic Acid(s) (typically refers to conjugated-double-bond isomers/mixtures of linoleic acid)
15. AA: Arachidonic Acid (20:4 n-6)
16. ALA: α-Linolenic Acid (18:3 n-3)
17. GLA: γ-Linolenic Acid (18:3 n-6)
18. EPA: Eicosapentaenoic Acid (20:5 n-3)
19. DHA: Docosahexaenoic Acid (22:6 n-3)
20. DPA: Docosapentaenoic Acid (22:5; can be n-3 or n-6 depending on the specific isomer)
21. GC: Gas Chromatography
22. GC-MS: Gas Chromatography–Mass Spectrometry
23. GC-FID: Gas Chromatography–Flame Ionization Detector
24. LC-MS: Liquid Chromatography–Mass Spectrometry
25. TBARS: Thiobarbituric Acid Reactive Substances (lipid-peroxidation–related readout)
26. MDA: Malondialdehyde (a common lipid peroxidation product)