**5. GC-TOF MS**

*Mass Spectrometry - Future Perceptions and Applications*

as the investigation of natural organic compounds or dioxin-related chemical compounds. The existence of modern HRMS instruments such as time-of-flight (TOF) and Orbitrap instruments has significantly changed the utilization of the equipment. Therefore, high-resolution mass spectrometry (HRMS) has gotten wider acceptance in the last decades for adulterant and residue analysis in food. This positive development is because of the availability of more versatile, robust, sensitive, and advanced instrumentation. The advantages by HRMS compared to classical unit-mass-resolution are ability to provide full-scan spectra, which offers more detail and insight into the mass composition of any sample. As a result, the analyst can measure chemical compounds without the necessity of compound-specific tuning, the need of retrospective data analysis, and has a capability performing an analysis of structural elucidations of suspected chemical compounds. HRMS is still preferable compared with classical hyphenated mass spectrometry in the investigation of quantitative multi residue methods (e.g., pesticides and veterinary drugs). It is one of the most powerful tools for identifying the unknown and non-targeted samples. Improvement of the hardware and software still needs to be addressed by the equipment manufacturers for it to be superior compared

*The observed chromatograms (XICs) for certain signature of myoglobin proteotypic peptide-fragment pairs. The spike was noticed in the chromatograms from beef samples with 1% horse meat (blue indicates extracted* 

to hyphenated mass spectrometry and to be a standard trace analysis tool.

to identify quite specific tryptic peptides from targeted proteins.

HRMS technology provides proteomic research to facilitate new discovery. The recent HRMS instruments already have the sensitivity, speed, accuracy, and selectivity to deliver comprehensive qualitative analysis, rapid chemical profiling, and high-accuracy analysis and detection of proteins in complex compounds. With these advantages, HRMS-based method was suitable specifically to perform the investigation of meat speciation and to detect food adulteration [73] and is capable

**98**

**Figure 7.**

*blank chromatograms) [73].*

GC-TOF MS instrument has two operation modes, in which one mode offers very high scan rates, allowing the segregation of overlapping spectrum peaks by automatically performing deconvolution mass spectral of overlapping spectrum signals [75]. Another type of GC-TOF MS instruments provides high mass resolution, performing data evaluation with a restricted mass window of 0.02 Da [76]. For ion separation GC-TOF MS, single-quad instruments are frequently utilized used. GC-MS systems with quadrupole ion traps integrated with time-of-flight (TOF) mass spectrometers or tandem mass spectrometers are used for the analysis of pure and mixture food.

### **5.1 Sample preparation**

The work by Witjaksono et al. [77] was conducted for total nine meat samples of three different animal meats, that is, chicken, cow, and pig. Each animal meat type is prepared to provide three different samples. The preparation of the animal meat samples and the extraction process of these animal body fats have been done using similar method mentioned before in the FTIR measurements. After obtaining the pure fats, each animal fat (approximately of 50 mg) was dissolved in 0.8 mL hexane. Later, the mixture was stirred for 1 min using an apparatus of vortex mixer and then stored in the dark at −18°C before going to GC-TOF MS analysis.

#### **5.2 GC-TOF MS results**

The analysis for this food adulteration was based on GC-TOF MS to identify and study their complex chemical compounds. The equipment used is an Agilent 7693 B GC integrated with TOF MS with hp-5ms column. The analysis was performed for all nine samples, consisting of three samples each from cow, lard, and chicken fats to investigate their aromatic hydrocarbons. The result suggests that the concentration of 1,2,3-trimethyl-benzene, indane, and undecane in lard fat are higher by 250, 14.5, and 1.28 times than chicken fat's concentrations, respectively, and higher by 91.4, 2.3, and 1.24 times higher than cow fat's concentrations, respectively. This initial result promises the possibility of finding biomarkers for non-halal food adulterants.

**Table 3** provides the obtained average area covered by each hydrocarbon that is coming from three samples to represent the composition weightage for the different fat types. From **Table 1**, it is obvious that lard is distinctive from the other animal fats in several hydrocarbon compositions. Here are the resulted hydrocarbons that give bigger percentage area in lard in comparison with the other fats: benzene, 1,2,3-trimethyl-; benzene, 1-methyl-3-(1-methylethyl)-; benzene, 1-methyl-4-propyl-; hexanedioic acid, bis(2-ethylhexyl)ester; p-cymene; tridecane; undecane. By using chemometric and bioinformatics analysis techniques, these results could be further analyzed to differentiate and separate the lard fat from the other animal fats.


#### **Table 3.**

*Resulted composition of aromatic hydrocarbons for lard, chicken, and cow fats [77].*
