Analaysis of Cosmetic Products by GasChromatography/Mass Spectrometry andFast-atom Bombardment Mass Spectrometry:When a Combined Approach is Successful†

R. Maffei Facino1*, M. Carini1, G. Aldini1, C. Marinello1, P. Traldi2 and R. Seraglia2

1Istituto Chimico Farmaceutico Tossicologico, University of Milan, Viale Abruzzi 42, 20131, Milan, Italy2CNR, Area della Ricerca, Corso Stati Uniti 4, 35020, Padua, Italy

Fast-atom bombardment mass spectrometry (FAB-MS, both in the positive- and negative-ion modes) and gaschromatography/mass spectrometry (GC/MS) were applied for the rapid identification of the main ingredientsof two widely employed cosmetic products, a mascara and a semipermanent hair dye. FAB-MS, on theuntreated product (hair dye) or on a crude methanol extract (mascara) gives an unequivocal fingerprint ofinvolatile constituents, i.e. surfactants, anionic (cetyl/stearyl soaps) in mascara and cationic (polyethoxylatedoleyl/linoleyl/ricinoleyl-methyl ammonium chloride) in the hair dye. GC/MS (n-hexane and chloroformextracts), detects hydrocarbons, volatile silicon compounds, perfume components, preservatives andantioxidants in mascara and fatty acids (C8–C18), dye solvents and 4 colouring agents: 2-amino-5-nitrophenol,HC Yellow 2 (N-2-hydroxyethyl-o-nitroaniline); O-(2-hydroxyethyl)-4-amino-3-nitrophenol and HC Red3,N-(2-hydroxyethyl)-2-nitro-p-phenylendiamine in the hair dye. These results demonstrate that the combinedFAB-MS and GC/MS approaches, enabling a complete picture of the constituents of the cosmetic matrix,provide an invaluable analytical tool for the quality control of cosmetics, a subject that has been ratherneglected to date. © 1997 by John Wiley & Sons, Ltd.

Received 13 May 1997; Revised 5 June 1997; Accepted 27 June 1997Rapid. Commun. Mass Spectrom. 11, 1329–1334 (1997)No. of Figures: 10 No. of Tables: 2 No. of Refs: 13

The quality control of a cosmetic product is not onlyimportant from a technological point of view, toguarantee to the consumer the expected cosmeticperformance and to verify that it satisfies the legislativerequirements, but above all to avoid the risk of toxicreactions due to contaminants. The inspection becomesurgent and essential when a toxic adverse reaction (e.g.cosmetic dermatitis) is experienced by a consumer and/or when fraudulence is suspected. This challenges theanalytical chemist to a difficult task, because of themulti-ingredient composition of cosmetic products, thewide variety of cosmetic formulations on the marketand the ever increasing availability of new raw materi-als (more than 8,000 raw materials and fragrancesingredients are available to the cosmetic chemist!).

Continuing our interest in the field of quality controlof cosmetics, raw materials and finished formula-tions,1–4 in the present work we evaluated the potentialof mass spectrometry for the rapid identification of themain components of two widely used “stay-on” prod-ucts, viz a mascara and a hair dye, both chosen becauseof the well known problem of toxicity associated withcolourants (and to their decomposition or by-products)since they are close to, or actually in contact withmucous membranes. The problem was approached by acombination of gas chromatography/mass spectrometry(GC/MS) and fast-atom bombardment mass spectrom-etry (FAB-MS) techniques, in an attempt to draw up aprotocol/guideline for the rapid analysis of thesepotentially irritant formulations.

EXPERIMENTAL

Chemicals and apparatus

All the solvents used were analytical grade (Merck,Bracco, Milan, Italy). The mascara and the direct hairdye were from commercial sources. GC/MS determina-tions were performed under the following experimentalconditions:

(a) Mascara. C. Erba (Milan, Italy) Fractovap modelgas chromatograph equipped with a capillary column(fused silica SE54, 25 m 3 0.32 mm i.d.); programmingtemperature: 70 °C-300 °C (7 °C/min); injector tem-perature: 270 °C; carrier gas helium (30 cm.s–1). Massspectrometer-ion trap detector (ITD 800, FinniganMAT Bremen, Germany); electron energy: 70 eV; traptemperature 200 °C; transfer line temperature 250 °C;released software version n.3 IBM XT.

(b) Hair dye. Shimadzu (Tokyo, Japan) GC/MS QP1000instrument equipped with a capillary column (fusedsilica SPB5); programming temperature: 70 °C-300 °C(7 °C/min); injector temperature: 270 °C; carrier gashelium (30 cm s–1); mass spectrometer quadrupole;electron energy 70 eV; source temperature 200 °C;software MSPAC 200.

Gas chromatography/Fourier Transform InfraredSpectroscopy studies (GC/FT-IR) were done on a(Hewlett Packard, Palo Alto, CA, USA) HP 5890 gaschromatograph linked to a HP5965A IRD modeloperating under the following conditions: capillarycolumn HP1 (25 m 3 0.5 mm i.d.); programmingtemperature 70 °C–280 °C (5 °C/min); injector tem-perature 270 °C; carrier gas helium (30 cm s–1); transferline 280 °C; flow cell 280 °C; computer HP 9000. FAB

†Presented at the 15th Informal Meeting on Mass Spectrometry,Smolenice, Slovak Republic, 12–16 May 1997*Correspondence to: R.M. Facino

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CCC 0951–4198/97/121329–06 $17.50 © 1997 by John Wiley & Sons, Ltd.

mass spectra were obtained on a VG (Manchester, UK)70–70 EQ instrument, employing argon atoms with 7kev kinetic energy; The FAB gun was manufactured byIon-Tech (Teddington, UK). Recordings in the positive-and negative-ion modes (matrix thioglycerol) weretaken at a resolution of 3000, with a run speed of 20s/decade. Data were processed by a Digital PDP8/Acomputer system.

Sample treatment

(a) Mascara. A 0.1 g sample was extracted by vortexingwith methanol (2 3 3 mL); the methanol extracts werecollected, filtered, concentrated in vacuo to small volumeand directly submitted to FAB-MS analysis. Anotheraliquot (0.1 g) was extracted by vortexing with 3 mL ofn-hexane and centrifuged for 3 min at 5000 rpm toseparate the inorganic material; the organic phase wasrecovered and the residue re-extracted with n-hexaneand then with chloroform (2 3 3 mL). All the organicextracts were combined, concentrated in vacuo todryness and taken up in n-hexane (0.5 mL): 1 µL aliquotswere injected into the GC/MS and GC/FT-IR systems.

(b) Semipermanent hair dye. The product (0.1 g sample)was analysed by FAB-MS after methanol solubilization.For GC/MS experiments, 0.1 g samples were dispersedin water (10 mL), adjusted to pH 1 with 1 N HCl andextracted with n-hexane (3 volumes; 2 times); the organicphases were collected and concentrated in vacuo to smallvolume (0.5 mL). The aqueous residue was re-extractedwith chloroform at different pH values (1, 7, 10) and thecombined organic extracts processed in the same way. 1µL aliquots of the n-hexane and chloroform extracts wereinjected into the GC/MS system. Thin layer chromato-graphic (TLC) analysis of the chloroform extract wascarried out by two-dimensional development usingtoluene + chloroform + acetone; 40:25:35 (solvent sys-tem 1) and methylethyl-ketone + butylacetate + wa-ter + methanol: 60:40:2:1 (solvent system 2) and colour-ants were detected under visible light.

RESULTS AND DISCUSSION

Mascara

Mascara is a matrix in which the dyes (inorganicpigments) are finely dispersed in a complex oil/wateremulsion. Since, as previously demonstrated,2 FAB-MSis a technique of choice for the characterization ofdifferent classes of surfactants, we analysed first byFAB-MS (positive- and negative-ion modes), a crudemethanol extract from a commercial mascara, toachieve an immediate indication of the emulsifyingagent. The positive-ion FAB mass spectrum of thecrude methanol extract does not show any diagnosticpeak, relative to non ionic, cationic or amphotericsurfactants (data not shown); by contrast, in thenegative-ion mass spectrum (Fig. 1) three peaks areclearly detectable at m/z 227, 255 and 283, whichcorrespond to the carboxylate anions [M-H]– of myris-tic (C14), palmitic (C16) and stearic (C18) acids. Fromthis pattern, the emulsifying agent was readily identi-fied as an alkali metal (sodium) soap.

For the characterization of the lipophilic compo-nents, the n-hexane + chloroform extract was then

submitted to GC/MS analysis (Fig. 2); several classes ofcompounds were identified:

(a) perfume components, such as terpenes (peak 1retention time (RT) 11.45 = α-pinene) or sesqui-terpenes (peaks 5–6 = â-gurjunene RT 16.44; car-yophyllene RT 16.58), the sesquiterpenyl alcoholfarnesol (peak 11, RT 19.00), p-hydroxybenzoicacid (peak 13, RT 20.55);

(b) the preservative mixture, mainly composed ofphenoxyethanol (peak 2 = RT 12.32, scan number744), and to a lesser extent of methylparaben andpropylparaben (peaks 7–8; RT 17.40 and 18.07);

(c) the antioxidant butylhydroxytoluene (BHT, peak10, RT 18.45);

(d) volatile silicon compounds (peaks 3, 4, 9, 12, 14, 18,whose mass spectra contain only a main peak atm/z 73, typical of a (CH3)3Si- moiety), probablybelonging to the class of dimethylpolysiloxanes(foam-suppressing agents).

Figure 1. Negative-ion FAB mass spectrum of mascara (crudemethanol extract).

Figure 2. GC/MS analysis of mascara (n-hexane + chloroformextract).

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The profile of the emulsifying mixture already identi-fied preliminarily by FAB-MS, was confirmed by GC/MS, from the peaks of myristic (peak 17, RT 23.13),palmitic (peak 22, RT 27.02), and stearic (peak 24, RT29.48) acids.

Peaks 15 [RT 22.00] and 16 [RT 22.49] show almostidentical spectra, with ions at m/z 138, 121 (base peak),92, 65, indicating esters of salicyclic acid with long-chainfatty alcohols, e.g. octyl salicylate or tridecyl salicylate(tentatively identified only: no library information);peak 19 [RT 24.37; ions at m/z 284, 129, 117 (basepeak), 75 and 55] was not identified. The main fractionof the lipophilic phase is constituted by a series ofhomologous compounds (peaks 20, 21, 23, 25–35; RTbetween 25 and 50 min) which show no molecular ionsbut almost identical fragmentation patterns, with ionsat m/z 43, 57, 71, 85, 99, 113 and 127; the distribution ofthe relative intensities (m/z 57 base peaks; m/z 43 and71 = 80 and 70%) are typical of saturated, unbranchedhydrocarbon chains (data not shown). This indicatesthat this commercial mascara contains low cost mineralwaxes, such as paraffin, ceresin, ozokerite or petrola-tum, all of which consist of high molecular weighthydrocarbons (derived from the higher petroleumfractions).

In an attempt to obtain a deeper insight into thecomposition of this fraction, the n-hexane + chloro-form extract was analysed in parallel by anothercombined technique, the GC/FTIR approach. Fig. 3reports the chromatogram obtained by injecting 1 µLsamples of the extract: the pattern is qualitativelysimilar to that obtained by GC/MS, but only the 13main peaks furnish diagnostic spectra. Peaks 1 (RT 5.45min), 2 (RT 15.2 min) and 3 (RT 17.2) were unequivo-cally confirmed as phenoxyethanol (Fig. 4), palmiticacid (Fig. 5) and stearic acid (data not shown). TheFTIR spectra of peaks 4-13 are typical of hydrocarbonderivatives, and give only the C-H stretchings at2932/2865 cm–1 and the CH3 and CH2 bendings at 1352and 1464 cm–1 (data not shown), but do not furnish

additional information to achieve definitive structuralassignment. Because of the lower sensitivity of IRdetection vs mass spectrometry (approximately 100 pgvs 100 ng), it was not possible to confirm the structureof peaks with retention times between those of phenox-yethanol (peak 1) and palmitic acid (peak 2), previouslyidentified by GC/MS as essential oils, preservatives,antioxidants, which are present in the cosmetic productin small amounts.

A rough estimate of the percentage composition ofthe product, obtained by determining first the amountof volatile matter (105 °C), then the amount of materialextractable with the organic solvent and finally theinorganic residue, gives a satisfactory profile of mascaraconstituents in terms of recovery (analytical details inTable 1), where inorganic pigments, identified asPigment Black 11 (Fe2O3) and Pigment Blue 29(Na8Al6SiS2O24) account for 8.5%.

Semipermanent hair dye

The FAB-MS plus GC/MS approach was applied to theanalysis of another widely used cosmetic product, a redsemipermanent hair dye. Semipermanent hair dyes, socalled because they will withstand five to six shampoo

Figure 3. GC/FTIR analysis of mascara (n-hexane + chloroformextract).

Figure 4. FTIR spectrum of peak 1.

Figure 5. FTIR spectrum of peak 2.

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© 1997 by John Wiley & Sons, Ltd. Rapid Communications in Mass Spectrometry, Vol. 11, 1329–1334 (1997)

Table 1. Percentage composition of mascara andsemipermanent hair dye

Mascara

Involatile matter (residue 105°C) = 42% (gravimetric)

n-hexane extract = 32% (gravimetric)(a) fatty acids = 8.5% (titration)12

(b) hydrocarbons, antioxidants, preservatives = 23.5%

Inorganic pigments = 8.5%(a) HCI soluble Pigment Black 11 = 5.5%(b) HCI insoluble Pigment Blue 29 = 3%

Aqueous residue (hydrolyzed cheratine)* = 1.5%

Semipermanent hair dye

Involatile matter (residue 105°C) = 22% (gravimetric)

n-hexane extract pH1 = 9%(a) fatty acids = 4.5% (titration)(b) ethoxylated fatty alcohols, antioxidants, etc. = 4.5%

CHCl3 extracts (different pH values)(a) hair dyes <5%

Cationic surfactants = 8% (titration)13

Aqueous residue ??? = 2%

* The only component reported on the label.

➝➝

washings, contain dye molecules (generally low molec-ular weight, nonionic) formulated in a more complexmatrix.

To obtain a rapid screening of the main ionic speciesof the cosmetic base, the product was again directlyanalysed by FAB-MS (loading a few µg of the productdissolved in methanol on the probe tip).

In the positive-ion mode three series of ions A,B,Cwere clearly detectable (Fig. 6):

A = m/z 414, 458, 502, 546, 590, 634, 678, 722, 766,810, 854, 898;

B = m/z 412, 456, 500, 544, 588, 632, 676, 720, 764,808, 852, 896;

C = m/z 430, 474, 518, 562, 606, 650, 694, 738, 782,826, 870, 914;

indicative of three series of homologous compoundswhich differ by 44u (ethoxylated derivatives). On thebasis of molecular weight and ion distribution, we

assigned to the three series the structures of poly-ethoxylated (n = 3-14) oleyl (A)/linoleyl(B)/ricino-leyl(C)-methylammonium chloride, a mixture of cati-onic tensides, widely used in hair products owing totheir conditioning and softening properties.

In the negative-ion FAB mass spectrum, the ions atm/z 143, 171, 199, 227, 255 and 283 (data not shown),which correspond to the carboxylate anions of caprylic(C8), capric (C10), lauric (C12), myristic (C14), palmitic(C16) and stearic (C18) acids, point to a mixture of fattyacids from a natural source (i.e. coconut).

Next we examined by GC/MS the organic extracts ofthe hair dye formulation: in the more lipophilic fraction(n-hexane, Fig. 7) 30 compounds were identified (Table2), among which were:

— perfume components (peaks 4, 11, 12, 18);— dye solvents (peaks 1 and 2);— antioxidants (peaks 9, 10);— C8–C18 fatty acids, already detected by FAB-MS,

negative-ion mode (peaks 3, 6, 13, 16, 20, 22);— fatty alcohols (peaks 8, 14) and the corresponding

ethoxylated derivatives: C16En(n = 1 → 6; peaks 15,21, 24, 26, 28, 30); C18En (n = 1 → 5; peaks 19, 23,25, 27, 29).

These compounds, which do not furnish molecular ions,were identified on the basis of their typical fragmenta-tion patterns, previously described in detail.1

Compounds 7 and 17 (only tentatively identifiedbecause of the poor library match as ethyllaurate andethylisostearate) are probably homologous compounds:they give almost identical fragmentation patterns(Table 2).

The colouring mixture was selectively and quantita-tively recovered in the chloroform extracts. The GC/MSprofile of this fraction (Fig. 8) shows four main peaks,all of them identified as the components of thecolouring matter on the basis of the molecular ions, thefragmentation patterns and the colour developed onTLC plates. Colour 1 (RT 21.24) was the only oneidentified by library match as 2-amino-5-nitrophenol(Fig. 9(a)), colour 2 (Fig. 9(b)) shows a molecular ion atm/z 182 and a fragmentation pattern governed by theloss of 31u (ion at m/z 151, base peak; M-CH2OH,typical of ethanolamine derivatives); the fragment ionsat m/z 121 (151 - 30) and 105 (151 - 46) typical of a nitro

Figure 6. Positive-ion FAB mass spectrum of the semipermanent hairdye.

Figure 7. GC/MS analysis of the semipermanent hair dye (n-hexaneextract).

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Table 2. Hair dye: mass spectral data of the components of the n-hexane extract

Peak RT (min) Scan number Ions (m/z) Assigned structure

1 6.48 206 108 [M]+; 91; 79 (b.p.); 77; 51 Phenylmethanol2 7.12 218 122 [M]+; 91 (b.p.); 65 Phenylethanol3 8.42 262 144 [M]+; 101; 85; 73; 60 (b.p.) Caprylic acid4 9.00 271 154 [M]+; 136; 121; 93; 71; 59 (b.p.) Terpineol5 11.50 347 214 [M]+; 125; 97; 83; 69; 54; 43 (b.p.) Myristyl alcohol (C14OH)6 13.00 391 172 [M]+; 129; 115; 101; 87; 73; 60 (b.p.); 43 Capric acid7 13.30 401 129; 115; 101; 88 (b.p.); 73 Not identified (ethyl-laurate?)8 14.54 449 242 [M]+; 111; 97; 83; 69; 55 (b.p.) Cetyl alcohol (C16OH)9 15.06 454 150 [M]+; 135 (b.p.); 115; 107; 91 2-t-butylphenol

10 15.30 466 220 [M]+; 205 (b.p.); 177; 145; 81; 57 Butylated hydroxytoluene (BHT)11 15.48 476 206 [M]+; 191; 150; 135; 121 (b.p.); 107; 93 α-Methyl-ionone12 16.06 485 208 [M]+; 138; 120 (b.p.); 92; 65 Amyl salicylate13 16.48 505 200 [M]+; 171; 157; 143; 129; 115; 101; 85; 73 (b.p.); 60; 43 Lauric acid14 18.60 560 270 [M]+; 125; 111; 97; 83; 69; 55 (b.p.) Stearyl alcohol (C18OH)15 19.30 582 Ref. 1 C16H33-OCH2CH2OH (C16E1)16 20.06 606 228 [M]+; 185; 129; 97; 73 (b.p.); 60; 43 Myristic acid17 20.50 616 129; 115; 101; 88 (b.p.); 73 Not identified (ethyl-isostearate?)18 21.54 660 228 [M]+; 91 (b.p.) Benzyl salicylate19 22.60 680 Ref. 1 C18H37-OCH2CH2OH (C18E1)20 23.12 698 256 [M]+; 213; 129; 97; 73; 60; 43 (b.p.) Palmitic acid21 23.70 712 Ref. 1 C16E2

22 26.00 782 284 [M]+; 241; 185; 129; 97; 73; 43 (b.p.) Stearic acid23 26.50 798 Ref. 1 C18E2

a

24 27.50 826 Ref. 1 C16E3

25 30.00 902 Ref. 1 C18E3

26 30.80 927 Ref. 1 C16E4

27 33.10 995 Ref. 1 C18E4

28 34.00 1022 Ref. 1 C16E5

29 36.80 1106 Ref. 1 C18E5

30 38.00 1142 Ref. 1 C16E6

a E represents an ethoxylated derivative.

group, indicate the compound to be HC Yellow 2(N-2-hydroxyethyl-o-nitroaniline). Colour 3 (orange)with molecular ion at m/z 198 and a fragmentationpattern with ions at m/z 167 (base peak), 137, 121similar to that of HC-Yellow 2, was identified asO-(2-hydroxyethyl)-4-amino-3-nitrophenol (Fig.10(a)); colour 4 (Fig. 10(b)) as HC Red 3,N-(2-hydroxyethyl)-2-nitro-p-phenylendiamine, withmolecular ion at m/z 197, and fragments at m/z 166 (M- 31), 136 and 119, shifted by one mass unit with respectto those of colour 3. The other minor peaks wereidentified as due to N-methyl-pyrrolidone (RT 8.12),lauramide DEA (diethanolamide of lauric acid; RT

19.24), t-butyl-cymene (RT 12.48), and diisooctylpha-late (RT 33.24), the first two being dye solvents.

The percentage composition of the product, estab-lished by gravimetric and titrimetric analyses, is shownin Table 1.

Figure 8. GC/MS analysis of the semipermanent hair dye (chloroformextracts). Figure 9. EI mass spectra of (a) colour 1 and (b) colour 2.

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CONCLUSIONS

The potentialities of mass spectrometry have hithertobeen demonstrated in several fields of interest, such aspharmacology, biochemistry, toxicology, environmentalpollution, clinical chemistry, etc. Surprisingly a field stilllacking a systematic investigation by mass spectroscop-ists is the cosmetic one, in which analysis is still carriedout by conventional/traditional methods which aretime-consuming, sometimes unreliable and which donot furnish an unequivocal characterization of theanalyte. This last becomes urgent because of theincreasing body of unwanted reactions (irritation is the

most common side effect to cosmetics) experienced bythe consumer. Several studies carried out in USA,5,6

Sweden,7 Spain,8 France,9 The Netherlands10,11 indicatethat 3 to 8% of adverse skin reactions are caused byhair colorants and up to 23% by eye make-upproducts.

The approach proposed here seems adequate tosatisfy the requirements outlined in the objectives, sinceit gives, at least from a qualitative point of view, a fairlycomplete picture of the functional and base ingredientsof these formulations, containing more than 30/40analytes each. Above all it is rapid and gives unequiv-ocal structural information, this last being of out-standing importance when the identification of thecausative allergen(s) is urgent for proper medicaltreatment. The percentage composition achieved forboth the cosmetics shows the method to offer asuccessful approach to the problems.

REFERENCES

1. U. Vettori, S. Issa, R. Maffei Facino and M. Carini, Biomed.Environ. Mass Spectrom. 17, 193 (1988).

2. R. Maffei Facino, M. Carini, P. Minghetti, G. Moneti, E. Arlandiniand S. Melis, Biomed. Environ. Mass Spectrom. 18, 673 (1989).

3. R. Maffei Facino, M. Carini, S. Sala, P. Minghetti and P. Traldi,Biomed. Environ. Mass Spectrom. 19, 493 (1990).

4. R. Maffei Facino, M. Carini, G. Depta, P. Bernardi and B. Casetta,J. Am. Oil Chem. Soc. 72, 1 (1995).

5. W. F. Schorr, Cutis 14, 844 (1974).6. R. M. Adams and H. I. Maibach, J. Am. Acad. Derm. 13, 1062

(1985).7. E. Skog, Contact Dermatitis 6, 449 (1980).8. C. Romaguera, J. M. G. Camarasa, A. Alomar and F. Grimalt,

Contact Dermatitis 9, 167 (1983).9. Z. Ngangu, M. Samsoen and J. Foussereaus, Dermatosen 31, 126

(1983).10. A. C. De Groot, Contact Dermatitis 17, 26 (1987).11. A. C. De Groot, D. P. Bruynzeel, J. D. Bos, H. L. van der Meeren,

T. van Joost, B. A. Jagtman and J. W. Weyland, Arch. Dermatol.124, 1525 (1988).

12. D. C. Abbott, Analyst 87, 286 (1962).13. H. K. Biswas and B. M. Mandal, Anal. Chem. 44, 1636 (1972).

Figure 10. EI mass spectra of (a) colour 3 and (b) colour 4.

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