Table 3 Advantages and disadvantages of the techniques used for pesticide detection in horticulture crops
Techniques | Advantages | Disadvantages | References |
|---|---|---|---|
High-performance liquid chromatography (HPLC) | Automated operation; flexible; appropriate for different types of analytes or samples; high separation power with sensitive detection; and highly accurate and duplicatable quantitative analysis. | High cost; coelution; complex for beginners or novices; it does not work for all samples; adsorbed compounds; less separation efficiency; and it is lacking of an ideal universal detector. | |
Gas chromatography (GC) | High efficiency for the separation of the components from complex mixtures in an adequate interval of time; multiple detectors with high sensitivity; and exact quantitation. | It is limited to thermally stable and volatile compounds; most of the gas chromatography detectors are destructive. | |
Mass spectrometry (MS) | Extremely sensitive; it easily detects sample’s unknown components compared to the other techniques such HPLC and GC; it is a rapid and precise technique; it is capable to be combining with other techniques such a HPLC (LC-MS) and GC (GC-MS); and it operates with very small sample amounts. | High cost and requires expert technician. | |
Flame ionization detector (FID) | It is inexpensive to acquire; simplicity; versatile; large linear range; low noise; good sensitivity and easy to operate. | The most common disadvantage of FID is its destructive nature; also, it is unable to couple directly to other GC detectors. | [75] |
Liquid chromatography (LC) | Its capacity of separating complex samples; combination with MS; higher resolution and sensitivity. | Instrumental complexity; increased analysis time | |
Electrochemical detector (ECD) | Low cost in real time; simplicity; miniaturization; and continuous analysis on diverse analytes | It takes a lot of time; sensitive (i.e. to the surrounding environment); requires redox elements to improve the power generation | |
Nitrogen–phosphorous detector | Obtention of qualitative information; high sensitivity for compounds which contain N and P; ratios of response of the N-P detector; less extensive sample clean-up, and good linear range. | It is a destructive technique; and it is not applicable for many analytes. | |
Flame photometric detector | Low cost; it is selective and sensitive; rapid technique; it is qualitative and quantitative in nature; and it can determine very low concentrations of compounds in the samples. | It works only with liquid samples; it cannot directly detect inert gases in the samples; it cannot measure the accurate concentration of the metal ion in the solution | [29] |
Electron capture detector | It is adjustable; higher electron densities and energies; it is simple and robust; low maintenance; non-destructive and very sensible. | Low linear dynamic range; presence of radioactive material (precautions for use) | [30] |
Colorimetric technique | It is easy to operate; quick response; long linear range of the quantitative assay; result accessible in less than 1 second; and it is sensitive. | It is expensive; it does not work in UV and IR regions; it cannot be used in colourless compound | |
Paper chromatography | Less time-consuming; it is cheaper than other techniques; simple; it is quite easy to be configurated and handled | This technique is not suitable for quantitative analysis and the separation of volatile substances (such as hydrocarbons and volatile fatty acids); it cannot be coupled with testing large numbers of samples; and it is very difficult to separate complex mixtures by using this technique | [74] |
Reversed-phase liquid chromatography | This technique provides greater solubility for polar analytes; sample recovery with little solvent evaporation in a short time; separation of complex samples; and it works with nontoxic solvents. | It is time-consuming | |
Near-infrared transmission spectroscopy | Quick and automatic; easy to use; high penetration depth; reproducible | Low sensitivity; its high cost | [117] |
Enzyme-linked immunosorbent assay | High specificity and sensitivity; simple procedure; high efficiency; and quantitative and qualitative analysis | Instability of this technique; insufficient level of sensitivity; laborious assay procedure | |
Nano-biosensors | Selectivity, sensitivity, rapid detection, and response | Its development and implementation can be very costly; and tedious process | [119] |