Name | Citronellal |
Synonyms | RHODINAL d-rhodinal Citronellal Levo-citronellal 2,3-Dihydrocitral Natural Citronellal 3,7-dimethyl-6-octena 3,7-Dimethyl-6-octenal 3,7-dimethyloct-6-enal 3,7-DIMETHYL-6-OCTEN-1-AL (3R)-3,7-dimethyloct-6-enal (4-chlorophenyl)(phenyl)methanone |
CAS | 106-23-0 |
EINECS | 203-376-6 |
InChI | InChI=1/C10H18O/c1-9(2)5-4-6-10(3)7-8-11/h5,8,10H,4,6-7H2,1-3H3/t10-/m1/s1 |
InChIKey | NEHNMFOYXAPHSD-UHFFFAOYSA-N |
Molecular Formula | C10H18O |
Molar Mass | 154.25 |
Density | 0.857g/mLat 25°C(lit.) |
Melting Point | -16°C (estimate) |
Boling Point | 207°C(lit.) |
Specific Rotation(α) | D25 +11.50° |
Flash Point | 169°F |
JECFA Number | 1220 |
Water Solubility | Slightly miscible with water and ethanol. |
Solubility | Soluble in ethanol and most non-volatile oils, slightly soluble in volatile oils and propylene glycol, insoluble in glycerol and water. |
Vapor Presure | 14 hPa (88 °C) |
Appearance | Colorless to yellowish liquid |
Specific Gravity | 0.858 (20/4℃) |
Color | Clear light yellow |
Merck | 14,2329 |
BRN | 1720789 |
PH | 7 (H2O) |
Storage Condition | Store below +30°C. |
Sensitive | Air Sensitive |
Explosive Limit | 1.2-4.5%(V) |
Refractive Index | n20/D 1.451(lit.) |
MDL | MFCD00038090 |
Physical and Chemical Properties | Density 0.85
|
Use | For the preparation of flavor, with strong lemon, citronella rose-like aroma |
Risk Codes | R38 - Irritating to the skin R43 - May cause sensitization by skin contact R51/53 - Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R36/37/38 - Irritating to eyes, respiratory system and skin. R22 - Harmful if swallowed |
Safety Description | S36/37 - Wear suitable protective clothing and gloves. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S37/39 - Wear suitable gloves and eye/face protection S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 - Wear suitable protective clothing. |
UN IDs | UN 3082 9/PG 3 |
WGK Germany | 3 |
RTECS | RH2140000 |
FLUKA BRAND F CODES | 8 |
TSCA | Yes |
HS Code | 29121900 |
Toxicity | LD50 orally in Rabbit: 2420 mg/kg LD50 dermal Rabbit > 2500 mg/kg |
There are three forms of d-,I-and dI-, and d Citronellal is mainly present in citronella oil and eucalyptus oil. The molecular weight is 154.25, the boiling point is 203~204 ℃, the relative density is 0.8510, the specific optical rotation is 10 018 ', and the refractive index is 1. 4467. z-citronellal mainly exists in lemon grass oil, boiling point 205~208 ℃, relative density is 0.8567, refractive index is 1. 4491, specific rotation is -30. Citronellal is a colorless or yellowish oily liquid with lemon, citronella and rose aroma. It is easily rearranged in acidic medium and becomes menthol. Citronellal is soluble in ethanol, acetone, ethyl acetate and other organic solvents, insoluble in glycerol and water.
It can be obtained by distillation separation from plant essential oils such as citronella oil, or it can be obtained by hydrogenation of citral or dehydrogenation of B- citronellol.
can be used as a raw material for the preparation of food flavor (GB2760-1996).
FEMA | 2307 | CITRONELLAL |
LogP | 3.62 at 25℃ |
NIST chemical information | Information provided by: webbook.nist.gov (external link) |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
essence and spice | citronellal is the main component of citronella oil, which naturally exists in essential oils such as lemon eucalyptus oil and citronella oil with contents of 75% ~ 80% and 30% ~ 40% respectively. This product is insoluble in water and glycerin, soluble in ethanol and oil, slightly soluble in propylene glycol. It has a strong, fresh, green citrus-like aroma with a slight woody aroma. Unstable when exposed to air, sunlight and alkali. Citronellal can form binary azeotropic substances with nitrobenzene, m-cresol, ethylene glycol, benzyl alcohol, acetophenone, etc. It is partially decomposed into isoflerol at 350°C. It is stored in the air to obtain not only isoflerol, but also partially oxidized to ()-citronella acid and form a peroxide. Hydroquinone can be added to inhibit its oxidation. Silver oxide is oxidized in ammonia to obtain citronella acid, and platinum black is used in 75% ethanol to catalyze hydrogenation to obtain 2,6-dimethyloctanal, ()-citronellol or ()-dihydrocitronellol can be obtained by catalyzing nickel at room temperature; Grignard reaction can also occur. Citronellal can be obtained from citronellol oxidation or catalytic dehydrogenation, or from citral catalytic hydrogenation. Since there is an asymmetric carbon atom in the molecule of citronellal, citronellal separated from natural essential oils has optical rotation. But the citronellal obtained from citral hydrogenation is a racemate and has no optical rotation. D-citronellal mainly exists in Java citronella oil (including 30% ~ 40%), L-citronellal mainly exists in lemon eucalyptus leaf oil (including 65% ~ 80%). There are two production methods: one is to vacuum distill the crude aldehyde from the essential oil, and then add and refine it with sodium bisulfite. Another method is the oxidation of citronellol. Because the aroma of citronellal is too strong, the chemical properties are not very stable, and only a small amount is used in low-grade lilac, lily of the valley and other cosmetics and mosquito-repellent fragrance. Citronellal is mainly used in soap and cosmetic essence formula with an dosage of less than 10%. IFRA has no restrictions. At present, there are not many citronellal used directly as a spice in China. A large amount of citronellal is used to synthesize hydroxycitronellal and levomenthol and other spices with wider uses. |
content analysis | determined by method 1 (hydroxylamine method) in aldehyde and ketone determination method (OT-7). The amount of sample taken is 1.1g. Let stand for 1h before titration. The equivalent factor (e) in the calculation is 77.13. Or by non-polar column method in GT-10-4. |
toxicity | ADI O.25 mg/kg(CE). |
usage limit | FEMA(mg/kg): soft drink 4.0; Cold drink 1.3; Candy 4.5; Baked food 4.7; Pudding 0.60; Gum candy 0.30. Moderate limit (FDA § 172.515,2000). |
use | GB 2760-96 specifies edible spices that are allowed to be used. Mainly used to prepare citrus and cherry flavors. It is mainly used as a raw material for the synthesis of citronellol, hydroxycitronellal, menthol, etc. Can be used in a small amount of low-grade lemon type, cologne type, magnolia type, lily of the valley type, honey type, fragrant Wei type and other flavors, mainly to highlight the effect of grass green. Citronellal is rarely used in advanced flavors, but cheap soap flavors are commonly used. It is mainly used to make vanilla alcohol and hydroxyl citronella vinegar. It is also used as a raw material for dihydrocoryone, and it is synthesized by isopurum menthol. Among them, hydroxycitronellal is one of the most valuable spices. used to prepare essence, with strong lemon and citronella rose-like aroma used as fixative, coordinating agent and variator, widely used in cosmetic essence; It is also a flavoring agent for beverages and foods. It can be extracted from citronella oil or prepared by acetylation and oxidation of isoeugenol. |
production method | the citronellal content in lemon eucalyptus oil is 80-90%, and the content in Java vanilla oil is 30-40%. it can be produced from natural plants by single separation method in industry. The synthesis method is mainly citronellal obtained from pinene through the stage of producing pinane, 3, 7-dimethyloctadiene-1, 6-and citronellol; it can also be produced by citronellol in the presence of lead-chromium catalyst Catalytic dehydrogenation to produce. In addition, citronellal can be prepared by hydrogenating lemon in isopropyl alcohol at a reaction temperature of 140 ℃ and a pressure of 14.7MPa using nickel formate or nickel supported on alumina and adding sodium carbonate as catalyst. the sub-fraction of citronella oil fractionation is crude citronellal and geraniol without terpenes. The crude citronellal is treated with a concentrated solution of sodium heavy sulfite, sodium hydroxide solution is added at 0°C, and then treated with benzene and pressure filtration. The solid is citronellal and sodium heavy sulfite adduct, which is used in sodium carbonate. Steam distillation to obtain pure citronellal. It is obtained by catalytic hydrogenation of citral. |
spontaneous combustion temperature | 202°C |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |