Green analytical chemistry metrics for evaluating the greenness of analytical procedures

Abstract

Green analytical chemistry (GAC) focuses on mitigating the adverse effects of analytical activities on human safety, human health, and environment. In addition to the 12 principles of GAC, proper GAC tools should be developed and employed to assess the greenness of different analytical assays. The 15 widely used GAC metrics, i.e., national environmental methods index (NEMI), advanced NEMI, assessment of green profile (AGP), chloroform-oriented toxicity estimation scale (ChlorTox Scale), Analytical Eco-Scale, Green Certificate Modified Eco-Scale, analytical method greenness score (AMGS), green analytical procedure index (GAPI), ComplexGAPI, red-green-blue (RGB) additive color model, RGB 12 algorithm, analytical greenness calculator (AGREE), AGREE preparation (AGREEprep), HEXAGON, and blue applicability grade index (BAGI), are selected as the typical tools. This article comprehensively presents and elucidates the principles, characteristics, merits, and demerits of 15 widely used GAC tools. This review is helpful for researchers to use the current GAC metrics to assess the environmental sustainability of analytical assays.

Keywords: Analytical methods; Environmental sustainability; Green analytical chemistry; Greenness metric.

Graphical abstract

Fig. 1

The number of published papers that related to these green analytical chemistry (GAC) tools up till the present moment. The keywords searched in the database of Web of Science are the corresponding metrics and analytical methods. CHEMS-1: chemical hazard evaluation for management strategies; NEMI: national environmental methods index; AGP: assessment of green profile; HPLC-EAT: high performance liquid chromatography-environmental assessment tool; AMVI: analytical method volume intensity; GAPI: green analytical procedure index; RGB: red-green-blue; AMGS: analytical method greenness score; AGREE: analytical greenness calculator; AGREEprep: AGREE preparation; BAGI: blue applicability grade index; ChlorTox Scale: chloroform-oriented toxicity estimation scale.

Fig. 2

The typical output pictogram of national environmental methods index (NEMI) and the examples of using NEMI for assessing the greenness of some selected analytical procedures. (A) The typical output pictogram of NEMI [19]. (B–D) Examples of using NEMI for assessing the greenness of some selected analytical procedures: determination of guaifenesin and bromhexine in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) coupled with liquid-liquid extraction (B), determination of oxytetracycline and bromhexine in spiked milk samples by high performance liquid chromatography-ultraviolet (HPLC-UV) (C), and simultaneous quantitative analysis of carbinoxamine maleate, paracetamol, and pseudoephedrine hydrochloride in their pure form and marketed combination by ultraviolet (D). PBT: persistent, bioaccumulative, and toxic chemicals. Reprint from Ref. [19] with permission.

Fig. 3

The typical output pictogram of advanced national environmental methods index (advanced NEMI) and the examples of using advanced NEMI for assessing the greenness of some selected analytical procedures. (A) The typical output pictogram of advanced NEMI [16]. (B–D) Examples of using advanced NEMI for assessing the greenness of some selected analytical procedures: determination of guaifenesin and bromhexine in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) coupled with liquid-liquid extraction (B), determination of oxytetracycline and bromhexine in spiked milk samples by high performance liquid chromatography-ultraviolet (HPLC-UV) (C), and simultaneous quantitative analysis of carbinoxamine maleate, paracetamol, and pseudoephedrine hydrochloride in their pure form and marketed combination by UV (D). Reprint from Ref. [16] with permission.

Fig. 4

The typical output pictogram of assessment of green profile (AGP) and the examples of using AGP for assessing the greenness of some selected analytical procedures. (A) The typical output pictogram of AGP [30]. (B–D) Examples of using AGP for assessing the greenness of some selected analytical procedures: determination of guaifenesin and bromhexine in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) coupled with liquid-liquid extraction (B), determination of oxytetracycline and bromhexine in spiked milk samples by high performance liquid chromatography-ultraviolet (HPLC-UV) (C), and simultaneous quantitative analysis of carbinoxamine maleate, paracetamol, and pseudoephedrine hydrochloride in their pure form and marketed combination by UV (D). Reprint from Ref. [30] with permission.

Fig. 5

The typical output pictogram of using both Analytical Eco-Scale and Green Certificate Modified Eco-Scale to assess the greenness of three selected analytical methods. (A) The typical output pictogram of Green Certificate Modified Eco-Scale [28]. (B–D) Examples of using both Analytical Eco-Scale and Green Certificate Modified Eco-Scale for assessing the greenness of some selected analytical procedures: a green high performance liquid chromatography-ultraviolet (HPLC-UV) method coupled with solid phase extraction (SPE) as sample processing procedure for the detection of sulfonamides residues in different animal-origin foods (B), a microscalec solid-liquid extraction (MSLE) assay using a miniaturized device combined with cleanup via dispersive micro-solid-phase extraction (DμSPE) for determination of n-alkanes in marine sediments by gas chromatography-mass spectrometry (GC-MS) (C), and a thin-layer chromatography-ultraviolet (TLC-UV) assay for simultaneous determination of norfloxacin and tinidazole (D). Reprint from Ref. [28] with permission.

Fig. 6

The typical output pictogram of green analytical procedure index (GAPI) and the examples of using GAPI for assessing the greenness of some selected analytical procedures. (A) The typical output pictogram of GAPI [30]. (B–D) Examples of using GAPI for assessing the greenness of some selected analytical procedures: monitoring of guaifenesin and bromohexine hydrochloride in human plasma by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) (B), determination of bromhexine and oxytetracycline residues in milk by high performance liquid chromatography-ultraviolet (HPLC-UV) (C), and determination of polycyclic aromatic hydrocarbons (PAHs) in real water samples using gas chromatography (GC) with flame ionization detection (FID) (D). Reprint from Ref. [30] with permission.

Fig. 7

The typical output pictogram of complex green analytical procedure index (ComplexGAPI) and the examples of using complex ComplexGAPI for assessing the greenness of some selected analytical procedures. (A) The typical output pictogram of complex ComplexGAPI [35]. (B–D) Examples of using complex ComplexGAPI for assessing the greenness of some selected analytical procedures: determination of dimethyl phthalate in beverage samples by a deep eutectic solvent-based ferrofluid assisted liquid-liquid microextraction method and monitoring by high performance liquid chromatography-ultraviolet (HPLC-UV) (B), a monolithic capsule phase microextraction method combined with HPLC-diode array detector (DAD) for monitoring of benzoyl urea insecticides in apple juice samples (C), and nanoparticle-modified carbon paste sensor for ultrasensitive detection of lignocaine and its metabolite residues in bovine food samples (D). Reprint from Ref. [35] with permission.

Fig. 8

The typical output pictogram of analytical greenness calculator (AGREE) and the examples of using AGREE for assessing the greenness of some selected analytical procedures. (A) The typical output pictogram of AGREE [34]. (B–D) Examples of using AGREE for assessing the greenness of some selected analytical procedures: simultaneous quantification of carvedilol and ivabradine in tablets by derivative synchronous spectrofluorimetric method (B), determination of paracetamol (PAR), aspirin (ASP), and diphenhydramine (DIPH) by high-performance thin layer chromatographic (HPTLC) (C), and determination of 16 polycyclic aromatic hydrocarbons in environmental water samples by gas chromatography-mass spectrometry (GC-MS) coupled with solid-phase extraction (D). Reprint from Ref. [34] with permission.

Fig. 9

The typical output pictogram of analytical greenness calculator preparation (AGREEprep) and the examples of using AGREEprep for assessing the greenness of some selected analytical procedures. (A) The typical output pictogram of AGREEprep [37]. (B–D) Examples of using AGREEprep for assessing the greenness of some selected analytical procedures: determination of tryptamine analogs in whole blood by 96-well electromembrane extraction and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) (B), determination of beta-blockers in serum by on-line liquid-liquid extraction coupled with UPLC-MS/MS (C), and simultaneous determination of paclitaxel and vincristine in environmental water and urine samples by dispersive micro solid phase extraction coupled with high performance liquid chromatography (HPLC) (D). Reprint from Ref. [37] with permission.

Fig. 10

The pictogram of red-green-blue (RGB) additive color model and RGB 12 algorithm. (A) The pictogram of RGB additive color model [31]. (B) The pictogram of RGB 12 algorithm. LOD: limit of detection; LOQ: limit of quantification; WAC: white analytical chemistry. Reprint from Ref. [31] with permission.

Fig. 11

The typical output pictogram of blue applicability grade index (BAGI) and the examples of using BAGI for assessing the greenness of some selected analytical procedures. (A) The typical output pictogram of BAGI [38]. (B–D) Examples of using BAGI for assessing the greenness of some selected analytical procedures: analysis of phthalates, polycyclic aromatic hydrocarbons, and pesticide residues in infant formula by single-run gas chromatography-mass spectrometry (GC-MS) method (B), analysis of endocrine disrupting chemicals in milk and environmental water samples by high performance liquid chromatography-ultraviolet (HPLC-UV) (C), and analysis of morpholine (MOR) in the pericarp of orange and apple fruit specimens by an innovative spectrofluorometric assay (D). Reprint from Ref. [38] with permission.

Fig. 12

The typical output pictogram of HEXAGON and the examples of using HEXAGON for assessing the greenness of some selected analytical procedures. (A) The typical output pictogram of HEXAGON [32]. (B–D) Examples of using HEXAGON for assessing the greenness of some selected analytical procedures: smart-chemometric spectrophotometric assay for determination of six gastric proton-pump inhibitors (B), liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for determination of hydrochlorothiazide (HCT) and five antihypertensive drugs (C), and liquid chromatography assay with diode array detector (HPLC-DAD) for determination of sulfonate-based dyes in meat samples (D). Reprint from Ref. [32] with permission.