scholarly journals Retention indices, relative response factors, and mass spectra of trifluoroethyl and heptafluorobutyl esters of carboxylic acids determined by capillary GC/MS

1990 ◽  
Author(s):  
S.K.-T. Yu ◽  
R.P. Vrana ◽  
J.B. Green
Keyword(s):  
Carboxylic Acids ◽  
Mass Spectra ◽  
Retention Indices ◽  
Capillary Gc ◽  
Response Factors ◽  
Relative Response ◽  
Esters Of Carboxylic Acids

Chemical Compounds from Femoral Gland Secretions of Male Iberian Rock Lizards, Lacerta monticola cyreni

2005 ◽  
Vol 60 (7-8) ◽  
pp. 632-636 ◽  
Author(s):  
Pilar López ◽  
José Martín
Keyword(s):  
Carboxylic Acids ◽  
Mass Spectra ◽  
Scent Marking ◽  
Health Condition ◽  
Lizard Species ◽  
Lipophilic Compounds ◽  
Esters Of Carboxylic Acids ◽  
The Social ◽  
High Interindividual Variability ◽  
Femoral Gland Secretions

In spite of the importance of chemoreception and chemical signals in the social organization of lizards, there are only a few studies examining the chemical composition of secretions of lizards used for scent marking. The secretion of the femoral glands of male Iberian rock lizards (Lacerta monticola cyreni) contains 44 lipophilic compounds, including several steroids (mainly cholesterol), and n-C6 to n-C22 carboxylic acids, and minor components such as esters of carboxylic acids, alcohols, squalene, and one lactone. These compounds were identified on the basis of mass spectra, obtained by GC-MS. Most lipids were detected in all individuals, although relative proportions of each chemical show a high interindividual variability. This variability might be related to the characteristics or physical and health condition of males and might be the basis of female choice based on chemical cues observed in this lizard species.

Age Related Differences in Lipophilic Compounds Found in Femoral Gland Secretions of Male Spiny-footed Lizards, Acanthodactylus erythrurus

2005 ◽  
Vol 60 (11-12) ◽  
pp. 915-920 ◽  
Author(s):  
Pilar López ◽  
José Martín
Keyword(s):  
Carboxylic Acids ◽  
Mass Spectra ◽  
Minor Components ◽  
Lipophilic Compounds ◽  
Femoral Glands ◽  
Age Related ◽  
Esters Of Carboxylic Acids ◽  
Intraspecific Communication ◽  
Femoral Gland Secretions ◽  
First Time

Although chemoreception plays an important role in social organization of many lizards, only a few studies have examined the chemicals found in secretions used for intraspecific communication. We report the composition of the secretion of the femoral glands of males of the spiny-footed lizard (Acanthodactylus erythrurus). On the basis of mass spectra, obtained by GC/MS, we identified 45 lipophilic compounds, including several alcohols ranging from 10 to 29 carbon atoms (mainly hexacosanol and tetracosanol), steroids (mainly cholesterol and dehydrocholesterol), n-C9 to n-C20 carboxylic acids, esters of carboxylic acids, and minor components such as lactones, ketones, squalene and α-tocopherol. Some of these compounds are reported for the first time in lizards. Adult and subadult males differed in the composition of secretions, with C9 to C15 carboxylic acids being more abundant in younger than in older lizards, whereas C16 to C20 carboxylic acids were more abundant in older lizards. Also, older lizards had significant lower proportions of cholesterol and campesterol but higher proportions of dehydrocholesterol.

Поправочные коэффициенты в формулах для расчета содержания примесей: сущность, способы определения и их ограничения

2019 ◽  
Vol 53 (5) ◽  
pp. 55-60 ◽  
Author(s):  
Наум Аронович Эпштейн
Keyword(s):  
Correction Factors ◽  
Response Factors ◽  
Relative Response

Представлены формулы для расчета коэффициентов относительной чувствительности RRF (relative response factors) и поправочных коэффициентов F (correction factors) примесей, а также формулы, необходимые для понимания сущности коэффициентов RRF и F. Рассмотрены основные способы определения поправочных коэффициентов и их ограничения (условия, выполнение которых необходимо для корректного определения RRF и F). Эти ограничения не отражены в Европейской фармакопее и в Фармакопее США, но от их учета зависит правильность определения значений поправочных коэффициентов. Приведены примеры и даны рекомендации для надежного определения и правильного использования поправочных коэффициентов.

scholarly journals Quantitative and Physical Evaluation of Patchouli Essential Oils Obtained from Different Sources of Pogostemon cablin

2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Norma Hussin ◽  
Luigi Mondello ◽  
Rosaria Costa ◽  
Paola Dugo ◽  
Nik Idris Nik Yusoff ◽  
...  
Keyword(s):  
Essential Oils ◽  
Internal Standard ◽  
Retention Indices ◽  
Raw Material ◽  
Volatile Constituent ◽  
Response Factors ◽  
Oil Storage ◽  
Valuable Product ◽  
Linear Retention Indices ◽  
One Year

Patchouli essential oil can be obtained from fresh, dried and fermented plant material. It is a highly valuable product in the fragrance industry and its quality changes depending upon raw material age and oil storage. In this work, patchouli essential oils derived from different treatments have been subjected to GC-FID quantitative analysis using an internal standard (ISTD) method with response factors (RF). Samples were obtained from i) fresh plants; ii) hydrodistillation of one year mature and fermented plants; iii) hydrodistillation of one year mature plants; iv) commercial products from Indonesia and Malaysia. Linear Retention Indices (LRI) for both polar and non-polar GC-MS analyses were also measured as a tool for qualitative analysis towards a homologous series of C7-C30 n-alkanes. The results obtained confirmed that, in all samples, patchouli alcohol was the main volatile constituent, with higher amount in lab-scale produced oils, compared with commercial samples. Other major compounds, in lab oils and commercial samples respectively, were: δ-guaiene, α-guaiene, pogostol, seychellene and α-patchoulene. Another 36 compounds were also found.

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